MOST iwo-cycle moaei engines can overhauled made perform once did candidates can Identify favorite engine has finally worn itself ragged after years faithful service maybe should consider re building instead putting retirement Parts frequently available procedures straightfor ward bring old friend back life H owto EWalt Wilson Overhaul Two-Cycle Engines MOST OF US have though worn out old engine can hobby number years have engines probably restored perform well have served us faithfully eventually did originally Spare parts usually availjust wore out use Few seem realize able manufacturer its foreign engine US distributor product line Local hobby shops fre quently stock can get needed parts Ideally would replace piston Left Sleeve bearing puilers Gator RC Products make removai easy some stubborn cases theyre necessity Right sleeve pulier features brass ring expands nut tightened compress pius slide hammer provide outward force 40 Model Aviation piston rings wrist pin connecting rod cylinder liner possibly crankshaft bearings complete overhaul Some times cost necessary parts will come close price new engine often old engine can over hauled substantially less Comparative costs should considered before embark ing overhauling project Disassembly cases removal carburetor cylinder head frontplate backplate obvious Caution fore disassembling engine lcok write down identifying features may indicate sides frontplate backplate go up sides cylinder head piston connecting rod go front engine no such features exist mark parts future reference reassembling engine may discover parts have nonsymmetrical features no obvious di rection indicated Gaskets should replaced gasket must reused should care fully removed before submerging parts cleaning solution Note side gasket faces parts screws different lengths note screws go AbouttheAuthor Walt Wilson started build ing solid model airplanes before WW II interest evolved through Control Line Radio Control several years raced tether cars winning scores tro phies held tether car world speed record 15177mph year mid-i 950s Since has very successful racing quarter midget cars stock cars several types stock-bodied drag race cars Along way set several track American Hot Rod Association world records wife Suzi currently very active sports car rallying Wilson has flying RO 15 years Pylon Racing Scale major areas interest has done virtually own engine preparation forms racing through years technical illustrator advanced manage ment currently publications super visor major electronics manufacturer St Louis Some engines have integral frontplates some cases piston connect ing rod cant removed removing cylinder liner engines sufficient clearance just slip off connecting rod crank pin just trying clean up engine after crash journey dirt may able wash wipe away enough foreign matter complete disas sembly However assured thor ough cleanup overhaul faithful power plant must remove piston connecting rod Most ABC Aluminum piston Brass sleeve hard Chrome plating cylinder liners dont fit crankcase very tightly can removed simply removing frontplate crankshaft possible pushing piston toward top bore Keep gently pushing sleeve will usually come out its stubborn piston doesnt fit tight enough Popsicle stick can inserted exhaust port pushed upward piston get sleeve started out put metal objects exhaust port Use wcod dont use much force piston connecting rod could damaged carbon varnish deposits exist around outside exhaust port sleeve may have removed before sleeve will slip out heavy-duty cleaning like luse automotive carbure tor cleaner auto parts store Use according directions can dont get hands Caution Engine parts made plastic will usually destroyed tf exposed solvent cleaner will remove burned congealed oil carbon varnish paint layers skin other non-metallic materials dipped cleaner will also pit discolor metal parts left too long also smells bad use wellventilated area Flush lots running water sleeve still wont come out Gator RC Products sells set pullers removing stubborn sleeves bearings good investment going very much engine work consist April 1986 41 correctly reassemble engine very Tools such heavy-duty puller homemade wire hook useful engine disas important note non-symmetrical features sembly Use care mar scratch parts stubborn remove disassembiing good example isthe small offset oil hole inthisconrod heat used help remove tight sleeve boiling water torch sleeve crankcase should both placed tops until cool avoid possible warpage split brass ring between tapered flat washer expands nut tightened threaded rod brass ring placed inside top sleeve nut tightened grip sleeve weighted slide hammer rod used knock out sleeve Unfortu nately last report Gator RC sleeve bearing pullers available larger engines pullers come two sizes 60-size sleeves smaller 60-size rear crankshaft bearings bearing puller may also fit some smaller engine sleeves Iron steel sleeves usually fit crank case tighter ABC sleeves almost always harder remove above-mentioned pullers arent available sleeve wont come out normal amount pulling pushing crankcase may heated boiling water aluminum crankcase will expand iron sleeve hopefully make easier remove crankcase should placed upside down top cylinder pan water being heated avoid warpage lay its side Its usually hot enough water comes boil Use oven mitt handle piece 062 music wire can bent hook grasp port sleeve pulling out Dont use hook unless plan replace sleeve may damage cylinder bore top port sleeve removed set crank case sleeve tops cool Caution Dont rest heated sleeve its side intend reuse Bearings crankshaft should checked play binding replace necessary Sometimes thorough cleaning bearings will correct binding caused dirt metal chips bearings can checked rotating crankshaft piston connecting rod removed feeling binding shaft should turn smoothly Usually bearings good free dirt chips after engine cleaned crankshaft oounterweight can turned approximately 900 bottom released will settle bottom position itself Heavy congealed oil frontplate bearings may prevent bearings good Dont assume bearings bad crankshaft wont settle itself good quality ball bearings kept clean theyll usually outlast rest engine cant feel catching binding bearings probably good Some engines designed rear crankshaft bearing supported frontplate fits bore crankcase checking bearings type engine piston connecting rod should removed frontplate reassembled crankcase bearings properly supported 42 Model Aviation Some engines such Supertigre X-60 have pin assure sleeve prop erly oriented aligned crankcase Other engine manufacturers K&B shown ThissleevefortheK&B65ccenglneshows sometimes use notches sleeve relative positions portsshouldyou flange alignment head screws forget reassembling exhaust port right will located higher sleeve intake ports centerand left 1-ln-dia hole 2 x4 makes handy holding fixture several rebuilding length wood dowel used drive operations performed 40-size front bearing out frontplate Wood frontpiate assembly Engines engine nevera metal punch should always used parts will ruined clamping vise avoid damage engine parts wood block used protect crank shaft seating rear bearing re seating will necessary after crash replacing bearings eltherthe crank pin connecting rod rub backplate 1 SCREW 2 GLOW PLUG 3 WASHER 4 HEAD 5 PISTON RING 6 PISTON 7 WRISTPIN 8 CONNECTING ROD 9 SLEEVE 10 CRANKCASE 11 EXHAUST ROTOR 12 BACKPLATE 13 EXHAUST ROTOR LEVER 14 LINK & SPRING 15 LOCKWASHER 16 SCREW 17 CARBURETOR 18O RING 19 CRANKSHAFT 20 REAR BALL BEARING 21 FRONTPLATE 22 FRONT BALL BEARING 23 PROP DRIVE HUB 24 PIN 25 SETSCREW 26 PROP ADAPTER STUD 27 PROP WASHER 28 PROP NUT 29 SETSCREW K&B 40 RC #8011 IllUSTRATION BY WALT & SUZI WILSON dont free up dunk dishwashing water few minutes slosh around try again Some people may agree procedure works bearings free feel smooth dry assembly paper towels blow out water much can oil crankshaft bearings liber ally Marvel Oil favorite light machine oil dont get out water oil steel parts well will rust Alcohol may used washing instead detergent/water detergent much less expensive least effective find impossible get bearings turn freely cleaning proceed follows Remove prop drive hub engines will fall off some cases may stubborn Try holding hub fingers tapping end crankshaft plastic hammer dont have plastic hammer regular hammer may used block wood softer metal such aluminum brass protect end crankshaft Caution Dont hit end crankshaft steel hammer may ruin threads Some engines such older K&B 40 may have drive hub pinned place and/or held place setscrew sure pins setscrews etc removed Small pullers usually available automotive tools sold will get job done else fails older K&B 40 necessary use hammer drift punch crankshaft re cessed hub K&B recommends 2 1 3 6 1 10 K13 r- i1 207 V Iill j2122 29 21 28 25 can test feel shaft bearings bearings become worn excessive ly bore frontplate between bearings will also wear allow fuel blow out through front bearing leakage appears excessive frontplate should also replaced Most engines blow fuel out front bearing some extent little bit blowby no indication excessive wear fact some blowby necessary lubricate front bearing modern engines have ball bearings crankshaft Some older less expensive engines have bronze bushings support crankshaft engine bronze bushing crankshaft shows excessive wear frontplate should replaced worn-out bronze-bushed frontplate integral crankcase would consider abandoning overhaul ing project Replacement crankcase addition other required parts very likely exceed price new engine have old engine bronze bushing badly worn parts no longer available may want investi gate knurling Automotive machine shops knurl worn auto engine valve guides replaceable ream original size may able to crankshaft bushing old model engine brainstorming havent yet occasion try Its possible alternative though really de- assembled frontplate returned terinined restore old engine factory service required cleaning replacing ball bearings hub removed try push out crankshaft must remove the crankshaft through bearings Fre crankshaft bearings quently crankshaft will push right out bearings frontplate dam- though luck usually wont aging anything First try clean doesnt push out try holding frontplate assembled frontplate bearings well tapping end crankshaft as engine parts soaking hot described above Again dont hit end water liquid dishwashing detergent crankshaft directly steel hamAfter few minutes remove frontplate merl doesnt work try supporting assembly solution flush frontplatewithwoodblocks drill hole running lukewarm water Rotate crank- 2 x 4 hole saw slightly larger shaft spin keep flushing bearings crankshaft counterbalance supporting water until feel smooth Continued page 126 April 198643 11 1 N 12N DG DESIGNS Full Body Pilot KIt Lightest Pilot available oLIfelIke vinyl la tex rubber parts Easy assemble finish eBulid either barnstormer sportsman pilot eKit contains pilot head hands boots helmet cap goggles full templates easy instructions eFully positionable & moveable Some simple sewing required Weight Price 116 Scale 2oz* $ 795 1/4 Scale 4 oz $ 995 1/3Scale 6oz $1695 Weight may vary depending material used construction DGA DESIGNS Bust Pilot Kit Weight 1/6Scale 75oz 1/4 Scale 1Soz 1/3 Scale 225 oz Price 595 795 $1495 Lightest bust pilot available eLifelike vinyl latex rubber parts Easy assemble finish Build either barnstormer sportsman pilot Kit contains pilot head helmet cap goggles jacket instructions See dealer order direct Add $100 shipping direct orders Send $100 current catalog Dealers inquiries invited NYS Aesidents add 7 percent sales tax Send Check MO Allow 3 weeks check clearSorry-NO CODs Ei1wu ml Radio Technique/Myers Continued page 123 can perform same kinds tests enough interest exists will spend few columns simple test techniques want send note either MA s publisher George M Myers 70 Froehlich Farm Rd Hicksville NY 11801 Engines/Wilson Continued page 43 frontplate hole try hitting crankshaft little harder cases will job else fails automotive machine shops have press will definitely remove crankshaft Inspect crankshaft scoring grooves discoloration crankpin area around between bearings crankshaft shows roughness wear areas should re placed Again look replacement price before proceeding usually expensive part indication outer races bearings have turning frontplate frontplate should also replaced next challenge removing bearings frontplate front bearing inner race almost always smaller bore frontplate piece wood dowel approximate size bore frontplate can used hammer tap out front bearing rear bearing tight enough stay crankshaft puller used remove drive hub will get off have Gator RC bearing puller removal rear bearing frontplate should no problem Otherwise try heating frontplate pan boiling water Hopefully aluminum frontplate will expand steel bearing outer race allowing removed sufficient room previouslymentioned wire hook may inserted through bearing inner bore help pull out Again use cooking mitt handle frontplate during procedure Reassembly New bearings should gent ly tapped place frontplate plastic hammer Tap around outer race being careful bearing goes bore evenly Dont let bearing get cocked bore crankshaft can used guide get bearing straight sure bearing tapped way bore Keep clean dont want ruin new bearings bearings place oil insert crankshaft prop drive hub K&B 40 must aligned pin holes setscrew match cor responding hole flat crankshaft engines fits tight must driven place hammer Again protect hub counterbalance crankshaft wood blocks ham mering pin hole hub aligned pin hole crankshaft drive roll pin place tighten setscrew other engines drive hub simply slips place Rotate crank shaft few times assure turning freely havent picked up dirt bearings Ring-type pistons sleeves piston rings available separately need purchased matched sets fit piston ring-type engine critical other types unless special racing engine being assembled Some engines have small pin ring groove hold ring given position respect ports carefully check such pin before installing ring piston Some rings such Dykes ring K&B 40 have top bottom cases direction obvious doubt look original piston ring Insert ring cylinder sleeve push little way piston square bore should gap about 0002 inch bore between ends ring no feeler gauge available check see light visible between ends clear ance probably okay engines bore i less no gap visible remove ring file sand ends slightly holding ends together rubbing thin file wet-or-dry sandpaper between File little check often its easy go too far ruin ring ring gap correct clean up ring sure no burrs around ends Carefully spread ring slip over top piston ring groove Align ends pin has Check fit big end connecting rod crankpin should bind does get another connecting rod its unlikely new connecting rod will fit properly Compare new connecting rod old de termine side goes front engine Frequently oil hole side big end fits crankshaft should face specific direction Pistons baffle fence top should have baffle toward intake ports Being sure parts clean facing proper direction oil assemble connecting rod piston inserting wrist pin Most wrist pins have pads ends made Teflon some other relatively soft material pre vent scuffing sleeve Make sure pads place Some wrist pins go way through piston have such pad instance pad obviously end will exposed sleeve area piston pin exposed should aligned ports sleeve Pistons/sleeves ABC engines 126 Model Aviation monthly publication covering International RC Soaring Scene $1 6/yr US Canada & Mexico $24/yr elsewhere via airmail Post Office Box 269 Peterborough NH 03458 justto get Spar 57 Area SOOsqot Weiglst 64 00 loadiug lOooInqft Eagine Requned 4 nyolo 40 2 cycle 2535 Rodio 4 channel loss instructions youll ever buy coos tell put oil money fantartic kit uut u fautastic bou comes hr Want kooro muse ahoot 440 other plaue aud electrouic hits Seud $200 116W 1911s55 PO Hou5L1EJ Hi8gicsoille 540 64077 call us 016 584-7121 order 44 1 00 lrorrdhssg ec Coming 460 NEW lapped iron pistons/sleeves available matched sets no fitting re quired ABC pistons designed fit sleeve tightly top stroke dont alarmed condition discovered heat running en gine expands sleeve piston proper clearance automatic Some ABC engines also use piston rings cases frontplate integral crankcase sleeve removed before piston connecting rod could removed will necessary reassemble piston connecting rod onto crankpin before sleeve inserted Slip piston sleeve bottom sleeve inserted crankcase sounds com plicated reasonable care its difficult engine piston rings must assembled way sleeve usually has tapered bore bottom assist compressing rings Some engines have clearance holes flange top sleeve head screws Some have alignment pin crankcase matches notch flange top sleeve Others have no alignment devices no alignment feature present obvious orienta tion sleeve crankcase may determined follows two-cycle model engine have encountered exhaust ports physi cally located nearer top sleeve intake ports Locate exhaust ports face toward exhaust port crankcase push sleeve place aligning ports crankcase ports go parts clean sleeve will almost always slip place no ringer pressure hangs up way make sure ports lined up place crankcase sleeve upside down clean surface such table push place firmly palm hand bottom crankcase event sleeve will push crankcase reasonable pres sure place sleeve freezer hour may cause sleeve contract enough go crankcase Check time assure ports sleeve aligned ports crankcase over ABC piston rod assembly must sleeve time sleeve assembled crankcase will impossible usually insert ABC piston through top sleeve due tight fit Insert bottom Iron pistons ring-type pistons may assembled sleeve after sleeve crankcase except course frontplate integral crankcase Oil piston wrist pin sleeve generously before assembly ABC iron pis tons simply oriented pushed sleeve proper direction Pistons rings require little effort aligning pin ring groove piston align ring gap pin no pin present ring gap should oriented line ports Push ring groove fingernails gently push piston sleeve may necessary maintain gentle pressure top piston holding ring against top sleeve finger pushing ring groove piston other fingernails its right piston will slip sleeve Align piston bore lower end connecting rod perpendicular centerline crankshaft gasket used place frontplate proper position gasket being reused put exactly same position facing same way removed No sealers necessary Oil crankpin align con necting rod slip frontplate place front crankcase backplate removed support connecting rod finger frontplate crankpin inserted dont go easily find outwhats wrong Dont force everything aproperly aligned will easily slip place Turn crankshaft few times assure everything moves smoothly Insert four frontplate screws snug Tighten little time going first screw directly opposite working around frontplate until tight Dont twist off strip threads crankcase isealuminum threads delicate Check once assure sleeve still aligned ports crankcase install cylinder head Most modern engines dont use head gas kets some use thin shims under head shim engine disassembled sure replaced reassembling Snug screws first tighten little time again going first screw directly opposite working around head Some engines use squish band head some cases specific clearance designated instructions come engine clearance can checked using product called Plastigage available various clearance ranges auto parts stores soft plastic material looks like wire small piece placed top piston will contact squish band flat outer diameter portion head protrudes cylinder before head installed Install head rotate crankshaft couple times remove head Check width mashed Plastigage scale came Dont worry about clearances connecting rod wrist pin allowing piston come closer two-cycle engine running compression combus Continued page 130 April 1986 127 W o hear lot about ocr 440 kit Wish its unique miug desigs 40 four sleoket flyr slum smooth shut just crcs beheor mken see outside loop whot menu Oke half thror / lIe Thurs euchoutmeur Ibis plane after fem ucrubatic maneurets uetves atent frayrd nuds llkr youoe just test flown full wale homehuilt.you feel I.C IOhe yuuoe floated through Now A/ n e iiiS dM/itliVthurs wltos Suuday/llport flying about . LAS 1 e four strokers quiet hut powerful traits ordy odd thdll Joy Ride 4 40 moro thiog eorr built ACE plane kit already know gearifyingit con prIde oucreloes designing moss complote kits offort SAILPLANE LAUNCH EQUIPMENT FOR EVERY S PORT WINCH source QUIET FLIGHT supplies hi-starts accessories electric motors & reducers batteries chutes braided nylon line tow line drums more. VISA MASTERCARD DAVEY 1Pm lE CoRPoRATmN ONE WOOD LANEMALVERNPA19355 215644-6772 SEND SASE FOR INFO Engines/Wilson Continued page 127 tion maintain constant down pressure piston Plastigage mashed out too wide clearance too close thicker shim combination shims shouldbe used Plastigage mashed out wide enough clearance too great thinner shim no shim should used clear ance correct clean off Plastigage piston head reassemble head engine gasket used backplate put place mount backplate engine Tighten screws previously described Rotate crankshaft sure crankpin and/or connecting rod rubbing backplate binding detected tighten propeller crankshaft hold ward doesnt cure problem remove frontplate Using wood block protect crankshaft tap back crankshaft center hammer sure crankshaft rear bearing fully seated forwardmost position Reassemble engine try again crankshaft bearings fully seated should no contact backplate fully-assembled engine turns feels free except case new ABC engine may bind top stroke screw fresh glow plug reassemble carburetor engine 0-ring hold down carburetor against 0-ring tight ening screws nut hold place overhauling procedures have finished engine can broken using same procedures new information article applies generally two-cycle front-intake RC engines conventional constructions Other types engines require somewhat different procedures have better way tasks please write let know Walt Wilson 3000 Persimmon Dr St Charles MO 63301 Addresses companies products mentioned GatorRC Products 3713 Pompano Dr Pensacola FL 32504 K&B Manufacturing 12152 Woodruff Ave Downey CA 90241 Marvel Oil Company Inc Port Ches ter NY 10573 Sealed Power Corp Plastigage 100 Terrace Plaza Muskegon MI 49443 RC Soaring/Pruss Continued page 49 next two years may also thank outgoing officers served two terms four years Warren Plohr LSF/334 Presi dent Larry Jolly LSF/3579 Vice-Presi dent Ken Bates LSF/604 Secretary Cal Sobczynski LSF/2487 Treasurer During 1985 seven gents names added Level V list bringing total up 46 Earle Latimer LSF/31 19 Lansing MI Terry Edmonds LSF/463 Iowa City IA Dale Harber LSF/1880 Yoder IN Charron Smith LSF/4093 Grand MI Richard Ransom LSF/4747 lonia MI Thomas Dickey LSF/3816 Gaithersburg MD Robert Schow LSF/166 Vienna VA Congratulations As column closing out word received Larry Jolly representing USA won first place South Africa flying first International F3H Cross-Country event ever held Larry flying original design Comet Details later article Larry himself Until next month good lift Dan Pruss 131 E Pennington Ln Plainfield IL 60544 RC Electrics/Kopski Continued page 51 lengths nichrome Because nichrome has relatively stable resistance temperature variation copper other conductive wire could used task temperature coefficient copper -many metals around plus % minus 5o per 100 C Thus value shunresistance would vary quite noticeably ambient internal temperature thereby rendering such metals useless purposes later wire used readily available modelers foam-cutting wire RC Modeler PO Box 487 Sierra Madre CA 91024 Cost $225 five-foot length postpaid As received wire measured little over three ohms sug gest confirm yours just sure information given di rectly applicable Ill try give sufficient detail just case can ac commodate somewhat different resist ances few words now before get how-to nittygritty Youll recall discussion last month about ohmmeter function multimeter measure resistance five-foot length nichrome wire set meter selector switch lowest resistance range short test leads together carefully zero ohms adjustment knob until meter pointer rests 0 ohms scale Its often good practice tape meter face gently fingertip sure needle has reached its true resting position connect test leads end nichrome wire Make sure leads make tight contactboth zeroing operation connection What should get 3 33 ohms 130 Model Aviation POW OM RETRIEVER HOBBY HAMMER $Q~ APPROXLENGTH7/Extra Tip INCLUDES$125 ONE STEEL AND ONE BRASS TIP Send check Money Order M &WMODELS PO Box 6627 Huntington Beach CA 92615 Add 150 Post & Hand Rae add 6% tax
Edition: Model Aviation - 1986/04
Page Numbers: 40, 41, 42, 43, 126, 127, 130
MOST iwo-cycle moaei engines can overhauled made perform once did candidates can Identify favorite engine has finally worn itself ragged after years faithful service maybe should consider re building instead putting retirement Parts frequently available procedures straightfor ward bring old friend back life H owto EWalt Wilson Overhaul Two-Cycle Engines MOST OF US have though worn out old engine can hobby number years have engines probably restored perform well have served us faithfully eventually did originally Spare parts usually availjust wore out use Few seem realize able manufacturer its foreign engine US distributor product line Local hobby shops fre quently stock can get needed parts Ideally would replace piston Left Sleeve bearing puilers Gator RC Products make removai easy some stubborn cases theyre necessity Right sleeve pulier features brass ring expands nut tightened compress pius slide hammer provide outward force 40 Model Aviation piston rings wrist pin connecting rod cylinder liner possibly crankshaft bearings complete overhaul Some times cost necessary parts will come close price new engine often old engine can over hauled substantially less Comparative costs should considered before embark ing overhauling project Disassembly cases removal carburetor cylinder head frontplate backplate obvious Caution fore disassembling engine lcok write down identifying features may indicate sides frontplate backplate go up sides cylinder head piston connecting rod go front engine no such features exist mark parts future reference reassembling engine may discover parts have nonsymmetrical features no obvious di rection indicated Gaskets should replaced gasket must reused should care fully removed before submerging parts cleaning solution Note side gasket faces parts screws different lengths note screws go AbouttheAuthor Walt Wilson started build ing solid model airplanes before WW II interest evolved through Control Line Radio Control several years raced tether cars winning scores tro phies held tether car world speed record 15177mph year mid-i 950s Since has very successful racing quarter midget cars stock cars several types stock-bodied drag race cars Along way set several track American Hot Rod Association world records wife Suzi currently very active sports car rallying Wilson has flying RO 15 years Pylon Racing Scale major areas interest has done virtually own engine preparation forms racing through years technical illustrator advanced manage ment currently publications super visor major electronics manufacturer St Louis Some engines have integral frontplates some cases piston connect ing rod cant removed removing cylinder liner engines sufficient clearance just slip off connecting rod crank pin just trying clean up engine after crash journey dirt may able wash wipe away enough foreign matter complete disas sembly However assured thor ough cleanup overhaul faithful power plant must remove piston connecting rod Most ABC Aluminum piston Brass sleeve hard Chrome plating cylinder liners dont fit crankcase very tightly can removed simply removing frontplate crankshaft possible pushing piston toward top bore Keep gently pushing sleeve will usually come out its stubborn piston doesnt fit tight enough Popsicle stick can inserted exhaust port pushed upward piston get sleeve started out put metal objects exhaust port Use wcod dont use much force piston connecting rod could damaged carbon varnish deposits exist around outside exhaust port sleeve may have removed before sleeve will slip out heavy-duty cleaning like luse automotive carbure tor cleaner auto parts store Use according directions can dont get hands Caution Engine parts made plastic will usually destroyed tf exposed solvent cleaner will remove burned congealed oil carbon varnish paint layers skin other non-metallic materials dipped cleaner will also pit discolor metal parts left too long also smells bad use wellventilated area Flush lots running water sleeve still wont come out Gator RC Products sells set pullers removing stubborn sleeves bearings good investment going very much engine work consist April 1986 41 correctly reassemble engine very Tools such heavy-duty puller homemade wire hook useful engine disas important note non-symmetrical features sembly Use care mar scratch parts stubborn remove disassembiing good example isthe small offset oil hole inthisconrod heat used help remove tight sleeve boiling water torch sleeve crankcase should both placed tops until cool avoid possible warpage split brass ring between tapered flat washer expands nut tightened threaded rod brass ring placed inside top sleeve nut tightened grip sleeve weighted slide hammer rod used knock out sleeve Unfortu nately last report Gator RC sleeve bearing pullers available larger engines pullers come two sizes 60-size sleeves smaller 60-size rear crankshaft bearings bearing puller may also fit some smaller engine sleeves Iron steel sleeves usually fit crank case tighter ABC sleeves almost always harder remove above-mentioned pullers arent available sleeve wont come out normal amount pulling pushing crankcase may heated boiling water aluminum crankcase will expand iron sleeve hopefully make easier remove crankcase should placed upside down top cylinder pan water being heated avoid warpage lay its side Its usually hot enough water comes boil Use oven mitt handle piece 062 music wire can bent hook grasp port sleeve pulling out Dont use hook unless plan replace sleeve may damage cylinder bore top port sleeve removed set crank case sleeve tops cool Caution Dont rest heated sleeve its side intend reuse Bearings crankshaft should checked play binding replace necessary Sometimes thorough cleaning bearings will correct binding caused dirt metal chips bearings can checked rotating crankshaft piston connecting rod removed feeling binding shaft should turn smoothly Usually bearings good free dirt chips after engine cleaned crankshaft oounterweight can turned approximately 900 bottom released will settle bottom position itself Heavy congealed oil frontplate bearings may prevent bearings good Dont assume bearings bad crankshaft wont settle itself good quality ball bearings kept clean theyll usually outlast rest engine cant feel catching binding bearings probably good Some engines designed rear crankshaft bearing supported frontplate fits bore crankcase checking bearings type engine piston connecting rod should removed frontplate reassembled crankcase bearings properly supported 42 Model Aviation Some engines such Supertigre X-60 have pin assure sleeve prop erly oriented aligned crankcase Other engine manufacturers K&B shown ThissleevefortheK&B65ccenglneshows sometimes use notches sleeve relative positions portsshouldyou flange alignment head screws forget reassembling exhaust port right will located higher sleeve intake ports centerand left 1-ln-dia hole 2 x4 makes handy holding fixture several rebuilding length wood dowel used drive operations performed 40-size front bearing out frontplate Wood frontpiate assembly Engines engine nevera metal punch should always used parts will ruined clamping vise avoid damage engine parts wood block used protect crank shaft seating rear bearing re seating will necessary after crash replacing bearings eltherthe crank pin connecting rod rub backplate 1 SCREW 2 GLOW PLUG 3 WASHER 4 HEAD 5 PISTON RING 6 PISTON 7 WRISTPIN 8 CONNECTING ROD 9 SLEEVE 10 CRANKCASE 11 EXHAUST ROTOR 12 BACKPLATE 13 EXHAUST ROTOR LEVER 14 LINK & SPRING 15 LOCKWASHER 16 SCREW 17 CARBURETOR 18O RING 19 CRANKSHAFT 20 REAR BALL BEARING 21 FRONTPLATE 22 FRONT BALL BEARING 23 PROP DRIVE HUB 24 PIN 25 SETSCREW 26 PROP ADAPTER STUD 27 PROP WASHER 28 PROP NUT 29 SETSCREW K&B 40 RC #8011 IllUSTRATION BY WALT & SUZI WILSON dont free up dunk dishwashing water few minutes slosh around try again Some people may agree procedure works bearings free feel smooth dry assembly paper towels blow out water much can oil crankshaft bearings liber ally Marvel Oil favorite light machine oil dont get out water oil steel parts well will rust Alcohol may used washing instead detergent/water detergent much less expensive least effective find impossible get bearings turn freely cleaning proceed follows Remove prop drive hub engines will fall off some cases may stubborn Try holding hub fingers tapping end crankshaft plastic hammer dont have plastic hammer regular hammer may used block wood softer metal such aluminum brass protect end crankshaft Caution Dont hit end crankshaft steel hammer may ruin threads Some engines such older K&B 40 may have drive hub pinned place and/or held place setscrew sure pins setscrews etc removed Small pullers usually available automotive tools sold will get job done else fails older K&B 40 necessary use hammer drift punch crankshaft re cessed hub K&B recommends 2 1 3 6 1 10 K13 r- i1 207 V Iill j2122 29 21 28 25 can test feel shaft bearings bearings become worn excessive ly bore frontplate between bearings will also wear allow fuel blow out through front bearing leakage appears excessive frontplate should also replaced Most engines blow fuel out front bearing some extent little bit blowby no indication excessive wear fact some blowby necessary lubricate front bearing modern engines have ball bearings crankshaft Some older less expensive engines have bronze bushings support crankshaft engine bronze bushing crankshaft shows excessive wear frontplate should replaced worn-out bronze-bushed frontplate integral crankcase would consider abandoning overhaul ing project Replacement crankcase addition other required parts very likely exceed price new engine have old engine bronze bushing badly worn parts no longer available may want investi gate knurling Automotive machine shops knurl worn auto engine valve guides replaceable ream original size may able to crankshaft bushing old model engine brainstorming havent yet occasion try Its possible alternative though really de- assembled frontplate returned terinined restore old engine factory service required cleaning replacing ball bearings hub removed try push out crankshaft must remove the crankshaft through bearings Fre crankshaft bearings quently crankshaft will push right out bearings frontplate dam- though luck usually wont aging anything First try clean doesnt push out try holding frontplate assembled frontplate bearings well tapping end crankshaft as engine parts soaking hot described above Again dont hit end water liquid dishwashing detergent crankshaft directly steel hamAfter few minutes remove frontplate merl doesnt work try supporting assembly solution flush frontplatewithwoodblocks drill hole running lukewarm water Rotate crank- 2 x 4 hole saw slightly larger shaft spin keep flushing bearings crankshaft counterbalance supporting water until feel smooth Continued page 126 April 198643 11 1 N 12N DG DESIGNS Full Body Pilot KIt Lightest Pilot available oLIfelIke vinyl la tex rubber parts Easy assemble finish eBulid either barnstormer sportsman pilot eKit contains pilot head hands boots helmet cap goggles full templates easy instructions eFully positionable & moveable Some simple sewing required Weight Price 116 Scale 2oz* $ 795 1/4 Scale 4 oz $ 995 1/3Scale 6oz $1695 Weight may vary depending material used construction DGA DESIGNS Bust Pilot Kit Weight 1/6Scale 75oz 1/4 Scale 1Soz 1/3 Scale 225 oz Price 595 795 $1495 Lightest bust pilot available eLifelike vinyl latex rubber parts Easy assemble finish Build either barnstormer sportsman pilot Kit contains pilot head helmet cap goggles jacket instructions See dealer order direct Add $100 shipping direct orders Send $100 current catalog Dealers inquiries invited NYS Aesidents add 7 percent sales tax Send Check MO Allow 3 weeks check clearSorry-NO CODs Ei1wu ml Radio Technique/Myers Continued page 123 can perform same kinds tests enough interest exists will spend few columns simple test techniques want send note either MA s publisher George M Myers 70 Froehlich Farm Rd Hicksville NY 11801 Engines/Wilson Continued page 43 frontplate hole try hitting crankshaft little harder cases will job else fails automotive machine shops have press will definitely remove crankshaft Inspect crankshaft scoring grooves discoloration crankpin area around between bearings crankshaft shows roughness wear areas should re placed Again look replacement price before proceeding usually expensive part indication outer races bearings have turning frontplate frontplate should also replaced next challenge removing bearings frontplate front bearing inner race almost always smaller bore frontplate piece wood dowel approximate size bore frontplate can used hammer tap out front bearing rear bearing tight enough stay crankshaft puller used remove drive hub will get off have Gator RC bearing puller removal rear bearing frontplate should no problem Otherwise try heating frontplate pan boiling water Hopefully aluminum frontplate will expand steel bearing outer race allowing removed sufficient room previouslymentioned wire hook may inserted through bearing inner bore help pull out Again use cooking mitt handle frontplate during procedure Reassembly New bearings should gent ly tapped place frontplate plastic hammer Tap around outer race being careful bearing goes bore evenly Dont let bearing get cocked bore crankshaft can used guide get bearing straight sure bearing tapped way bore Keep clean dont want ruin new bearings bearings place oil insert crankshaft prop drive hub K&B 40 must aligned pin holes setscrew match cor responding hole flat crankshaft engines fits tight must driven place hammer Again protect hub counterbalance crankshaft wood blocks ham mering pin hole hub aligned pin hole crankshaft drive roll pin place tighten setscrew other engines drive hub simply slips place Rotate crank shaft few times assure turning freely havent picked up dirt bearings Ring-type pistons sleeves piston rings available separately need purchased matched sets fit piston ring-type engine critical other types unless special racing engine being assembled Some engines have small pin ring groove hold ring given position respect ports carefully check such pin before installing ring piston Some rings such Dykes ring K&B 40 have top bottom cases direction obvious doubt look original piston ring Insert ring cylinder sleeve push little way piston square bore should gap about 0002 inch bore between ends ring no feeler gauge available check see light visible between ends clear ance probably okay engines bore i less no gap visible remove ring file sand ends slightly holding ends together rubbing thin file wet-or-dry sandpaper between File little check often its easy go too far ruin ring ring gap correct clean up ring sure no burrs around ends Carefully spread ring slip over top piston ring groove Align ends pin has Check fit big end connecting rod crankpin should bind does get another connecting rod its unlikely new connecting rod will fit properly Compare new connecting rod old de termine side goes front engine Frequently oil hole side big end fits crankshaft should face specific direction Pistons baffle fence top should have baffle toward intake ports Being sure parts clean facing proper direction oil assemble connecting rod piston inserting wrist pin Most wrist pins have pads ends made Teflon some other relatively soft material pre vent scuffing sleeve Make sure pads place Some wrist pins go way through piston have such pad instance pad obviously end will exposed sleeve area piston pin exposed should aligned ports sleeve Pistons/sleeves ABC engines 126 Model Aviation monthly publication covering International RC Soaring Scene $1 6/yr US Canada & Mexico $24/yr elsewhere via airmail Post Office Box 269 Peterborough NH 03458 justto get Spar 57 Area SOOsqot Weiglst 64 00 loadiug lOooInqft Eagine Requned 4 nyolo 40 2 cycle 2535 Rodio 4 channel loss instructions youll ever buy coos tell put oil money fantartic kit uut u fautastic bou comes hr Want kooro muse ahoot 440 other plaue aud electrouic hits Seud $200 116W 1911s55 PO Hou5L1EJ Hi8gicsoille 540 64077 call us 016 584-7121 order 44 1 00 lrorrdhssg ec Coming 460 NEW lapped iron pistons/sleeves available matched sets no fitting re quired ABC pistons designed fit sleeve tightly top stroke dont alarmed condition discovered heat running en gine expands sleeve piston proper clearance automatic Some ABC engines also use piston rings cases frontplate integral crankcase sleeve removed before piston connecting rod could removed will necessary reassemble piston connecting rod onto crankpin before sleeve inserted Slip piston sleeve bottom sleeve inserted crankcase sounds com plicated reasonable care its difficult engine piston rings must assembled way sleeve usually has tapered bore bottom assist compressing rings Some engines have clearance holes flange top sleeve head screws Some have alignment pin crankcase matches notch flange top sleeve Others have no alignment devices no alignment feature present obvious orienta tion sleeve crankcase may determined follows two-cycle model engine have encountered exhaust ports physi cally located nearer top sleeve intake ports Locate exhaust ports face toward exhaust port crankcase push sleeve place aligning ports crankcase ports go parts clean sleeve will almost always slip place no ringer pressure hangs up way make sure ports lined up place crankcase sleeve upside down clean surface such table push place firmly palm hand bottom crankcase event sleeve will push crankcase reasonable pres sure place sleeve freezer hour may cause sleeve contract enough go crankcase Check time assure ports sleeve aligned ports crankcase over ABC piston rod assembly must sleeve time sleeve assembled crankcase will impossible usually insert ABC piston through top sleeve due tight fit Insert bottom Iron pistons ring-type pistons may assembled sleeve after sleeve crankcase except course frontplate integral crankcase Oil piston wrist pin sleeve generously before assembly ABC iron pis tons simply oriented pushed sleeve proper direction Pistons rings require little effort aligning pin ring groove piston align ring gap pin no pin present ring gap should oriented line ports Push ring groove fingernails gently push piston sleeve may necessary maintain gentle pressure top piston holding ring against top sleeve finger pushing ring groove piston other fingernails its right piston will slip sleeve Align piston bore lower end connecting rod perpendicular centerline crankshaft gasket used place frontplate proper position gasket being reused put exactly same position facing same way removed No sealers necessary Oil crankpin align con necting rod slip frontplate place front crankcase backplate removed support connecting rod finger frontplate crankpin inserted dont go easily find outwhats wrong Dont force everything aproperly aligned will easily slip place Turn crankshaft few times assure everything moves smoothly Insert four frontplate screws snug Tighten little time going first screw directly opposite working around frontplate until tight Dont twist off strip threads crankcase isealuminum threads delicate Check once assure sleeve still aligned ports crankcase install cylinder head Most modern engines dont use head gas kets some use thin shims under head shim engine disassembled sure replaced reassembling Snug screws first tighten little time again going first screw directly opposite working around head Some engines use squish band head some cases specific clearance designated instructions come engine clearance can checked using product called Plastigage available various clearance ranges auto parts stores soft plastic material looks like wire small piece placed top piston will contact squish band flat outer diameter portion head protrudes cylinder before head installed Install head rotate crankshaft couple times remove head Check width mashed Plastigage scale came Dont worry about clearances connecting rod wrist pin allowing piston come closer two-cycle engine running compression combus Continued page 130 April 1986 127 W o hear lot about ocr 440 kit Wish its unique miug desigs 40 four sleoket flyr slum smooth shut just crcs beheor mken see outside loop whot menu Oke half thror / lIe Thurs euchoutmeur Ibis plane after fem ucrubatic maneurets uetves atent frayrd nuds llkr youoe just test flown full wale homehuilt.you feel I.C IOhe yuuoe floated through Now A/ n e iiiS dM/itliVthurs wltos Suuday/llport flying about . LAS 1 e four strokers quiet hut powerful traits ordy odd thdll Joy Ride 4 40 moro thiog eorr built ACE plane kit already know gearifyingit con prIde oucreloes designing moss complote kits offort SAILPLANE LAUNCH EQUIPMENT FOR EVERY S PORT WINCH source QUIET FLIGHT supplies hi-starts accessories electric motors & reducers batteries chutes braided nylon line tow line drums more. VISA MASTERCARD DAVEY 1Pm lE CoRPoRATmN ONE WOOD LANEMALVERNPA19355 215644-6772 SEND SASE FOR INFO Engines/Wilson Continued page 127 tion maintain constant down pressure piston Plastigage mashed out too wide clearance too close thicker shim combination shims shouldbe used Plastigage mashed out wide enough clearance too great thinner shim no shim should used clear ance correct clean off Plastigage piston head reassemble head engine gasket used backplate put place mount backplate engine Tighten screws previously described Rotate crankshaft sure crankpin and/or connecting rod rubbing backplate binding detected tighten propeller crankshaft hold ward doesnt cure problem remove frontplate Using wood block protect crankshaft tap back crankshaft center hammer sure crankshaft rear bearing fully seated forwardmost position Reassemble engine try again crankshaft bearings fully seated should no contact backplate fully-assembled engine turns feels free except case new ABC engine may bind top stroke screw fresh glow plug reassemble carburetor engine 0-ring hold down carburetor against 0-ring tight ening screws nut hold place overhauling procedures have finished engine can broken using same procedures new information article applies generally two-cycle front-intake RC engines conventional constructions Other types engines require somewhat different procedures have better way tasks please write let know Walt Wilson 3000 Persimmon Dr St Charles MO 63301 Addresses companies products mentioned GatorRC Products 3713 Pompano Dr Pensacola FL 32504 K&B Manufacturing 12152 Woodruff Ave Downey CA 90241 Marvel Oil Company Inc Port Ches ter NY 10573 Sealed Power Corp Plastigage 100 Terrace Plaza Muskegon MI 49443 RC Soaring/Pruss Continued page 49 next two years may also thank outgoing officers served two terms four years Warren Plohr LSF/334 Presi dent Larry Jolly LSF/3579 Vice-Presi dent Ken Bates LSF/604 Secretary Cal Sobczynski LSF/2487 Treasurer During 1985 seven gents names added Level V list bringing total up 46 Earle Latimer LSF/31 19 Lansing MI Terry Edmonds LSF/463 Iowa City IA Dale Harber LSF/1880 Yoder IN Charron Smith LSF/4093 Grand MI Richard Ransom LSF/4747 lonia MI Thomas Dickey LSF/3816 Gaithersburg MD Robert Schow LSF/166 Vienna VA Congratulations As column closing out word received Larry Jolly representing USA won first place South Africa flying first International F3H Cross-Country event ever held Larry flying original design Comet Details later article Larry himself Until next month good lift Dan Pruss 131 E Pennington Ln Plainfield IL 60544 RC Electrics/Kopski Continued page 51 lengths nichrome Because nichrome has relatively stable resistance temperature variation copper other conductive wire could used task temperature coefficient copper -many metals around plus % minus 5o per 100 C Thus value shunresistance would vary quite noticeably ambient internal temperature thereby rendering such metals useless purposes later wire used readily available modelers foam-cutting wire RC Modeler PO Box 487 Sierra Madre CA 91024 Cost $225 five-foot length postpaid As received wire measured little over three ohms sug gest confirm yours just sure information given di rectly applicable Ill try give sufficient detail just case can ac commodate somewhat different resist ances few words now before get how-to nittygritty Youll recall discussion last month about ohmmeter function multimeter measure resistance five-foot length nichrome wire set meter selector switch lowest resistance range short test leads together carefully zero ohms adjustment knob until meter pointer rests 0 ohms scale Its often good practice tape meter face gently fingertip sure needle has reached its true resting position connect test leads end nichrome wire Make sure leads make tight contactboth zeroing operation connection What should get 3 33 ohms 130 Model Aviation POW OM RETRIEVER HOBBY HAMMER $Q~ APPROXLENGTH7/Extra Tip INCLUDES$125 ONE STEEL AND ONE BRASS TIP Send check Money Order M &WMODELS PO Box 6627 Huntington Beach CA 92615 Add 150 Post & Hand Rae add 6% tax
Edition: Model Aviation - 1986/04
Page Numbers: 40, 41, 42, 43, 126, 127, 130
MOST iwo-cycle moaei engines can overhauled made perform once did candidates can Identify favorite engine has finally worn itself ragged after years faithful service maybe should consider re building instead putting retirement Parts frequently available procedures straightfor ward bring old friend back life H owto EWalt Wilson Overhaul Two-Cycle Engines MOST OF US have though worn out old engine can hobby number years have engines probably restored perform well have served us faithfully eventually did originally Spare parts usually availjust wore out use Few seem realize able manufacturer its foreign engine US distributor product line Local hobby shops fre quently stock can get needed parts Ideally would replace piston Left Sleeve bearing puilers Gator RC Products make removai easy some stubborn cases theyre necessity Right sleeve pulier features brass ring expands nut tightened compress pius slide hammer provide outward force 40 Model Aviation piston rings wrist pin connecting rod cylinder liner possibly crankshaft bearings complete overhaul Some times cost necessary parts will come close price new engine often old engine can over hauled substantially less Comparative costs should considered before embark ing overhauling project Disassembly cases removal carburetor cylinder head frontplate backplate obvious Caution fore disassembling engine lcok write down identifying features may indicate sides frontplate backplate go up sides cylinder head piston connecting rod go front engine no such features exist mark parts future reference reassembling engine may discover parts have nonsymmetrical features no obvious di rection indicated Gaskets should replaced gasket must reused should care fully removed before submerging parts cleaning solution Note side gasket faces parts screws different lengths note screws go AbouttheAuthor Walt Wilson started build ing solid model airplanes before WW II interest evolved through Control Line Radio Control several years raced tether cars winning scores tro phies held tether car world speed record 15177mph year mid-i 950s Since has very successful racing quarter midget cars stock cars several types stock-bodied drag race cars Along way set several track American Hot Rod Association world records wife Suzi currently very active sports car rallying Wilson has flying RO 15 years Pylon Racing Scale major areas interest has done virtually own engine preparation forms racing through years technical illustrator advanced manage ment currently publications super visor major electronics manufacturer St Louis Some engines have integral frontplates some cases piston connect ing rod cant removed removing cylinder liner engines sufficient clearance just slip off connecting rod crank pin just trying clean up engine after crash journey dirt may able wash wipe away enough foreign matter complete disas sembly However assured thor ough cleanup overhaul faithful power plant must remove piston connecting rod Most ABC Aluminum piston Brass sleeve hard Chrome plating cylinder liners dont fit crankcase very tightly can removed simply removing frontplate crankshaft possible pushing piston toward top bore Keep gently pushing sleeve will usually come out its stubborn piston doesnt fit tight enough Popsicle stick can inserted exhaust port pushed upward piston get sleeve started out put metal objects exhaust port Use wcod dont use much force piston connecting rod could damaged carbon varnish deposits exist around outside exhaust port sleeve may have removed before sleeve will slip out heavy-duty cleaning like luse automotive carbure tor cleaner auto parts store Use according directions can dont get hands Caution Engine parts made plastic will usually destroyed tf exposed solvent cleaner will remove burned congealed oil carbon varnish paint layers skin other non-metallic materials dipped cleaner will also pit discolor metal parts left too long also smells bad use wellventilated area Flush lots running water sleeve still wont come out Gator RC Products sells set pullers removing stubborn sleeves bearings good investment going very much engine work consist April 1986 41 correctly reassemble engine very Tools such heavy-duty puller homemade wire hook useful engine disas important note non-symmetrical features sembly Use care mar scratch parts stubborn remove disassembiing good example isthe small offset oil hole inthisconrod heat used help remove tight sleeve boiling water torch sleeve crankcase should both placed tops until cool avoid possible warpage split brass ring between tapered flat washer expands nut tightened threaded rod brass ring placed inside top sleeve nut tightened grip sleeve weighted slide hammer rod used knock out sleeve Unfortu nately last report Gator RC sleeve bearing pullers available larger engines pullers come two sizes 60-size sleeves smaller 60-size rear crankshaft bearings bearing puller may also fit some smaller engine sleeves Iron steel sleeves usually fit crank case tighter ABC sleeves almost always harder remove above-mentioned pullers arent available sleeve wont come out normal amount pulling pushing crankcase may heated boiling water aluminum crankcase will expand iron sleeve hopefully make easier remove crankcase should placed upside down top cylinder pan water being heated avoid warpage lay its side Its usually hot enough water comes boil Use oven mitt handle piece 062 music wire can bent hook grasp port sleeve pulling out Dont use hook unless plan replace sleeve may damage cylinder bore top port sleeve removed set crank case sleeve tops cool Caution Dont rest heated sleeve its side intend reuse Bearings crankshaft should checked play binding replace necessary Sometimes thorough cleaning bearings will correct binding caused dirt metal chips bearings can checked rotating crankshaft piston connecting rod removed feeling binding shaft should turn smoothly Usually bearings good free dirt chips after engine cleaned crankshaft oounterweight can turned approximately 900 bottom released will settle bottom position itself Heavy congealed oil frontplate bearings may prevent bearings good Dont assume bearings bad crankshaft wont settle itself good quality ball bearings kept clean theyll usually outlast rest engine cant feel catching binding bearings probably good Some engines designed rear crankshaft bearing supported frontplate fits bore crankcase checking bearings type engine piston connecting rod should removed frontplate reassembled crankcase bearings properly supported 42 Model Aviation Some engines such Supertigre X-60 have pin assure sleeve prop erly oriented aligned crankcase Other engine manufacturers K&B shown ThissleevefortheK&B65ccenglneshows sometimes use notches sleeve relative positions portsshouldyou flange alignment head screws forget reassembling exhaust port right will located higher sleeve intake ports centerand left 1-ln-dia hole 2 x4 makes handy holding fixture several rebuilding length wood dowel used drive operations performed 40-size front bearing out frontplate Wood frontpiate assembly Engines engine nevera metal punch should always used parts will ruined clamping vise avoid damage engine parts wood block used protect crank shaft seating rear bearing re seating will necessary after crash replacing bearings eltherthe crank pin connecting rod rub backplate 1 SCREW 2 GLOW PLUG 3 WASHER 4 HEAD 5 PISTON RING 6 PISTON 7 WRISTPIN 8 CONNECTING ROD 9 SLEEVE 10 CRANKCASE 11 EXHAUST ROTOR 12 BACKPLATE 13 EXHAUST ROTOR LEVER 14 LINK & SPRING 15 LOCKWASHER 16 SCREW 17 CARBURETOR 18O RING 19 CRANKSHAFT 20 REAR BALL BEARING 21 FRONTPLATE 22 FRONT BALL BEARING 23 PROP DRIVE HUB 24 PIN 25 SETSCREW 26 PROP ADAPTER STUD 27 PROP WASHER 28 PROP NUT 29 SETSCREW K&B 40 RC #8011 IllUSTRATION BY WALT & SUZI WILSON dont free up dunk dishwashing water few minutes slosh around try again Some people may agree procedure works bearings free feel smooth dry assembly paper towels blow out water much can oil crankshaft bearings liber ally Marvel Oil favorite light machine oil dont get out water oil steel parts well will rust Alcohol may used washing instead detergent/water detergent much less expensive least effective find impossible get bearings turn freely cleaning proceed follows Remove prop drive hub engines will fall off some cases may stubborn Try holding hub fingers tapping end crankshaft plastic hammer dont have plastic hammer regular hammer may used block wood softer metal such aluminum brass protect end crankshaft Caution Dont hit end crankshaft steel hammer may ruin threads Some engines such older K&B 40 may have drive hub pinned place and/or held place setscrew sure pins setscrews etc removed Small pullers usually available automotive tools sold will get job done else fails older K&B 40 necessary use hammer drift punch crankshaft re cessed hub K&B recommends 2 1 3 6 1 10 K13 r- i1 207 V Iill j2122 29 21 28 25 can test feel shaft bearings bearings become worn excessive ly bore frontplate between bearings will also wear allow fuel blow out through front bearing leakage appears excessive frontplate should also replaced Most engines blow fuel out front bearing some extent little bit blowby no indication excessive wear fact some blowby necessary lubricate front bearing modern engines have ball bearings crankshaft Some older less expensive engines have bronze bushings support crankshaft engine bronze bushing crankshaft shows excessive wear frontplate should replaced worn-out bronze-bushed frontplate integral crankcase would consider abandoning overhaul ing project Replacement crankcase addition other required parts very likely exceed price new engine have old engine bronze bushing badly worn parts no longer available may want investi gate knurling Automotive machine shops knurl worn auto engine valve guides replaceable ream original size may able to crankshaft bushing old model engine brainstorming havent yet occasion try Its possible alternative though really de- assembled frontplate returned terinined restore old engine factory service required cleaning replacing ball bearings hub removed try push out crankshaft must remove the crankshaft through bearings Fre crankshaft bearings quently crankshaft will push right out bearings frontplate dam- though luck usually wont aging anything First try clean doesnt push out try holding frontplate assembled frontplate bearings well tapping end crankshaft as engine parts soaking hot described above Again dont hit end water liquid dishwashing detergent crankshaft directly steel hamAfter few minutes remove frontplate merl doesnt work try supporting assembly solution flush frontplatewithwoodblocks drill hole running lukewarm water Rotate crank- 2 x 4 hole saw slightly larger shaft spin keep flushing bearings crankshaft counterbalance supporting water until feel smooth Continued page 126 April 198643 11 1 N 12N DG DESIGNS Full Body Pilot KIt Lightest Pilot available oLIfelIke vinyl la tex rubber parts Easy assemble finish eBulid either barnstormer sportsman pilot eKit contains pilot head hands boots helmet cap goggles full templates easy instructions eFully positionable & moveable Some simple sewing required Weight Price 116 Scale 2oz* $ 795 1/4 Scale 4 oz $ 995 1/3Scale 6oz $1695 Weight may vary depending material used construction DGA DESIGNS Bust Pilot Kit Weight 1/6Scale 75oz 1/4 Scale 1Soz 1/3 Scale 225 oz Price 595 795 $1495 Lightest bust pilot available eLifelike vinyl latex rubber parts Easy assemble finish Build either barnstormer sportsman pilot Kit contains pilot head helmet cap goggles jacket instructions See dealer order direct Add $100 shipping direct orders Send $100 current catalog Dealers inquiries invited NYS Aesidents add 7 percent sales tax Send Check MO Allow 3 weeks check clearSorry-NO CODs Ei1wu ml Radio Technique/Myers Continued page 123 can perform same kinds tests enough interest exists will spend few columns simple test techniques want send note either MA s publisher George M Myers 70 Froehlich Farm Rd Hicksville NY 11801 Engines/Wilson Continued page 43 frontplate hole try hitting crankshaft little harder cases will job else fails automotive machine shops have press will definitely remove crankshaft Inspect crankshaft scoring grooves discoloration crankpin area around between bearings crankshaft shows roughness wear areas should re placed Again look replacement price before proceeding usually expensive part indication outer races bearings have turning frontplate frontplate should also replaced next challenge removing bearings frontplate front bearing inner race almost always smaller bore frontplate piece wood dowel approximate size bore frontplate can used hammer tap out front bearing rear bearing tight enough stay crankshaft puller used remove drive hub will get off have Gator RC bearing puller removal rear bearing frontplate should no problem Otherwise try heating frontplate pan boiling water Hopefully aluminum frontplate will expand steel bearing outer race allowing removed sufficient room previouslymentioned wire hook may inserted through bearing inner bore help pull out Again use cooking mitt handle frontplate during procedure Reassembly New bearings should gent ly tapped place frontplate plastic hammer Tap around outer race being careful bearing goes bore evenly Dont let bearing get cocked bore crankshaft can used guide get bearing straight sure bearing tapped way bore Keep clean dont want ruin new bearings bearings place oil insert crankshaft prop drive hub K&B 40 must aligned pin holes setscrew match cor responding hole flat crankshaft engines fits tight must driven place hammer Again protect hub counterbalance crankshaft wood blocks ham mering pin hole hub aligned pin hole crankshaft drive roll pin place tighten setscrew other engines drive hub simply slips place Rotate crank shaft few times assure turning freely havent picked up dirt bearings Ring-type pistons sleeves piston rings available separately need purchased matched sets fit piston ring-type engine critical other types unless special racing engine being assembled Some engines have small pin ring groove hold ring given position respect ports carefully check such pin before installing ring piston Some rings such Dykes ring K&B 40 have top bottom cases direction obvious doubt look original piston ring Insert ring cylinder sleeve push little way piston square bore should gap about 0002 inch bore between ends ring no feeler gauge available check see light visible between ends clear ance probably okay engines bore i less no gap visible remove ring file sand ends slightly holding ends together rubbing thin file wet-or-dry sandpaper between File little check often its easy go too far ruin ring ring gap correct clean up ring sure no burrs around ends Carefully spread ring slip over top piston ring groove Align ends pin has Check fit big end connecting rod crankpin should bind does get another connecting rod its unlikely new connecting rod will fit properly Compare new connecting rod old de termine side goes front engine Frequently oil hole side big end fits crankshaft should face specific direction Pistons baffle fence top should have baffle toward intake ports Being sure parts clean facing proper direction oil assemble connecting rod piston inserting wrist pin Most wrist pins have pads ends made Teflon some other relatively soft material pre vent scuffing sleeve Make sure pads place Some wrist pins go way through piston have such pad instance pad obviously end will exposed sleeve area piston pin exposed should aligned ports sleeve Pistons/sleeves ABC engines 126 Model Aviation monthly publication covering International RC Soaring Scene $1 6/yr US Canada & Mexico $24/yr elsewhere via airmail Post Office Box 269 Peterborough NH 03458 justto get Spar 57 Area SOOsqot Weiglst 64 00 loadiug lOooInqft Eagine Requned 4 nyolo 40 2 cycle 2535 Rodio 4 channel loss instructions youll ever buy coos tell put oil money fantartic kit uut u fautastic bou comes hr Want kooro muse ahoot 440 other plaue aud electrouic hits Seud $200 116W 1911s55 PO Hou5L1EJ Hi8gicsoille 540 64077 call us 016 584-7121 order 44 1 00 lrorrdhssg ec Coming 460 NEW lapped iron pistons/sleeves available matched sets no fitting re quired ABC pistons designed fit sleeve tightly top stroke dont alarmed condition discovered heat running en gine expands sleeve piston proper clearance automatic Some ABC engines also use piston rings cases frontplate integral crankcase sleeve removed before piston connecting rod could removed will necessary reassemble piston connecting rod onto crankpin before sleeve inserted Slip piston sleeve bottom sleeve inserted crankcase sounds com plicated reasonable care its difficult engine piston rings must assembled way sleeve usually has tapered bore bottom assist compressing rings Some engines have clearance holes flange top sleeve head screws Some have alignment pin crankcase matches notch flange top sleeve Others have no alignment devices no alignment feature present obvious orienta tion sleeve crankcase may determined follows two-cycle model engine have encountered exhaust ports physi cally located nearer top sleeve intake ports Locate exhaust ports face toward exhaust port crankcase push sleeve place aligning ports crankcase ports go parts clean sleeve will almost always slip place no ringer pressure hangs up way make sure ports lined up place crankcase sleeve upside down clean surface such table push place firmly palm hand bottom crankcase event sleeve will push crankcase reasonable pres sure place sleeve freezer hour may cause sleeve contract enough go crankcase Check time assure ports sleeve aligned ports crankcase over ABC piston rod assembly must sleeve time sleeve assembled crankcase will impossible usually insert ABC piston through top sleeve due tight fit Insert bottom Iron pistons ring-type pistons may assembled sleeve after sleeve crankcase except course frontplate integral crankcase Oil piston wrist pin sleeve generously before assembly ABC iron pis tons simply oriented pushed sleeve proper direction Pistons rings require little effort aligning pin ring groove piston align ring gap pin no pin present ring gap should oriented line ports Push ring groove fingernails gently push piston sleeve may necessary maintain gentle pressure top piston holding ring against top sleeve finger pushing ring groove piston other fingernails its right piston will slip sleeve Align piston bore lower end connecting rod perpendicular centerline crankshaft gasket used place frontplate proper position gasket being reused put exactly same position facing same way removed No sealers necessary Oil crankpin align con necting rod slip frontplate place front crankcase backplate removed support connecting rod finger frontplate crankpin inserted dont go easily find outwhats wrong Dont force everything aproperly aligned will easily slip place Turn crankshaft few times assure everything moves smoothly Insert four frontplate screws snug Tighten little time going first screw directly opposite working around frontplate until tight Dont twist off strip threads crankcase isealuminum threads delicate Check once assure sleeve still aligned ports crankcase install cylinder head Most modern engines dont use head gas kets some use thin shims under head shim engine disassembled sure replaced reassembling Snug screws first tighten little time again going first screw directly opposite working around head Some engines use squish band head some cases specific clearance designated instructions come engine clearance can checked using product called Plastigage available various clearance ranges auto parts stores soft plastic material looks like wire small piece placed top piston will contact squish band flat outer diameter portion head protrudes cylinder before head installed Install head rotate crankshaft couple times remove head Check width mashed Plastigage scale came Dont worry about clearances connecting rod wrist pin allowing piston come closer two-cycle engine running compression combus Continued page 130 April 1986 127 W o hear lot about ocr 440 kit Wish its unique miug desigs 40 four sleoket flyr slum smooth shut just crcs beheor mken see outside loop whot menu Oke half thror / lIe Thurs euchoutmeur Ibis plane after fem ucrubatic maneurets uetves atent frayrd nuds llkr youoe just test flown full wale homehuilt.you feel I.C IOhe yuuoe floated through Now A/ n e iiiS dM/itliVthurs wltos Suuday/llport flying about . LAS 1 e four strokers quiet hut powerful traits ordy odd thdll Joy Ride 4 40 moro thiog eorr built ACE plane kit already know gearifyingit con prIde oucreloes designing moss complote kits offort SAILPLANE LAUNCH EQUIPMENT FOR EVERY S PORT WINCH source QUIET FLIGHT supplies hi-starts accessories electric motors & reducers batteries chutes braided nylon line tow line drums more. VISA MASTERCARD DAVEY 1Pm lE CoRPoRATmN ONE WOOD LANEMALVERNPA19355 215644-6772 SEND SASE FOR INFO Engines/Wilson Continued page 127 tion maintain constant down pressure piston Plastigage mashed out too wide clearance too close thicker shim combination shims shouldbe used Plastigage mashed out wide enough clearance too great thinner shim no shim should used clear ance correct clean off Plastigage piston head reassemble head engine gasket used backplate put place mount backplate engine Tighten screws previously described Rotate crankshaft sure crankpin and/or connecting rod rubbing backplate binding detected tighten propeller crankshaft hold ward doesnt cure problem remove frontplate Using wood block protect crankshaft tap back crankshaft center hammer sure crankshaft rear bearing fully seated forwardmost position Reassemble engine try again crankshaft bearings fully seated should no contact backplate fully-assembled engine turns feels free except case new ABC engine may bind top stroke screw fresh glow plug reassemble carburetor engine 0-ring hold down carburetor against 0-ring tight ening screws nut hold place overhauling procedures have finished engine can broken using same procedures new information article applies generally two-cycle front-intake RC engines conventional constructions Other types engines require somewhat different procedures have better way tasks please write let know Walt Wilson 3000 Persimmon Dr St Charles MO 63301 Addresses companies products mentioned GatorRC Products 3713 Pompano Dr Pensacola FL 32504 K&B Manufacturing 12152 Woodruff Ave Downey CA 90241 Marvel Oil Company Inc Port Ches ter NY 10573 Sealed Power Corp Plastigage 100 Terrace Plaza Muskegon MI 49443 RC Soaring/Pruss Continued page 49 next two years may also thank outgoing officers served two terms four years Warren Plohr LSF/334 Presi dent Larry Jolly LSF/3579 Vice-Presi dent Ken Bates LSF/604 Secretary Cal Sobczynski LSF/2487 Treasurer During 1985 seven gents names added Level V list bringing total up 46 Earle Latimer LSF/31 19 Lansing MI Terry Edmonds LSF/463 Iowa City IA Dale Harber LSF/1880 Yoder IN Charron Smith LSF/4093 Grand MI Richard Ransom LSF/4747 lonia MI Thomas Dickey LSF/3816 Gaithersburg MD Robert Schow LSF/166 Vienna VA Congratulations As column closing out word received Larry Jolly representing USA won first place South Africa flying first International F3H Cross-Country event ever held Larry flying original design Comet Details later article Larry himself Until next month good lift Dan Pruss 131 E Pennington Ln Plainfield IL 60544 RC Electrics/Kopski Continued page 51 lengths nichrome Because nichrome has relatively stable resistance temperature variation copper other conductive wire could used task temperature coefficient copper -many metals around plus % minus 5o per 100 C Thus value shunresistance would vary quite noticeably ambient internal temperature thereby rendering such metals useless purposes later wire used readily available modelers foam-cutting wire RC Modeler PO Box 487 Sierra Madre CA 91024 Cost $225 five-foot length postpaid As received wire measured little over three ohms sug gest confirm yours just sure information given di rectly applicable Ill try give sufficient detail just case can ac commodate somewhat different resist ances few words now before get how-to nittygritty Youll recall discussion last month about ohmmeter function multimeter measure resistance five-foot length nichrome wire set meter selector switch lowest resistance range short test leads together carefully zero ohms adjustment knob until meter pointer rests 0 ohms scale Its often good practice tape meter face gently fingertip sure needle has reached its true resting position connect test leads end nichrome wire Make sure leads make tight contactboth zeroing operation connection What should get 3 33 ohms 130 Model Aviation POW OM RETRIEVER HOBBY HAMMER $Q~ APPROXLENGTH7/Extra Tip INCLUDES$125 ONE STEEL AND ONE BRASS TIP Send check Money Order M &WMODELS PO Box 6627 Huntington Beach CA 92615 Add 150 Post & Hand Rae add 6% tax
Edition: Model Aviation - 1986/04
Page Numbers: 40, 41, 42, 43, 126, 127, 130
MOST iwo-cycle moaei engines can overhauled made perform once did candidates can Identify favorite engine has finally worn itself ragged after years faithful service maybe should consider re building instead putting retirement Parts frequently available procedures straightfor ward bring old friend back life H owto EWalt Wilson Overhaul Two-Cycle Engines MOST OF US have though worn out old engine can hobby number years have engines probably restored perform well have served us faithfully eventually did originally Spare parts usually availjust wore out use Few seem realize able manufacturer its foreign engine US distributor product line Local hobby shops fre quently stock can get needed parts Ideally would replace piston Left Sleeve bearing puilers Gator RC Products make removai easy some stubborn cases theyre necessity Right sleeve pulier features brass ring expands nut tightened compress pius slide hammer provide outward force 40 Model Aviation piston rings wrist pin connecting rod cylinder liner possibly crankshaft bearings complete overhaul Some times cost necessary parts will come close price new engine often old engine can over hauled substantially less Comparative costs should considered before embark ing overhauling project Disassembly cases removal carburetor cylinder head frontplate backplate obvious Caution fore disassembling engine lcok write down identifying features may indicate sides frontplate backplate go up sides cylinder head piston connecting rod go front engine no such features exist mark parts future reference reassembling engine may discover parts have nonsymmetrical features no obvious di rection indicated Gaskets should replaced gasket must reused should care fully removed before submerging parts cleaning solution Note side gasket faces parts screws different lengths note screws go AbouttheAuthor Walt Wilson started build ing solid model airplanes before WW II interest evolved through Control Line Radio Control several years raced tether cars winning scores tro phies held tether car world speed record 15177mph year mid-i 950s Since has very successful racing quarter midget cars stock cars several types stock-bodied drag race cars Along way set several track American Hot Rod Association world records wife Suzi currently very active sports car rallying Wilson has flying RO 15 years Pylon Racing Scale major areas interest has done virtually own engine preparation forms racing through years technical illustrator advanced manage ment currently publications super visor major electronics manufacturer St Louis Some engines have integral frontplates some cases piston connect ing rod cant removed removing cylinder liner engines sufficient clearance just slip off connecting rod crank pin just trying clean up engine after crash journey dirt may able wash wipe away enough foreign matter complete disas sembly However assured thor ough cleanup overhaul faithful power plant must remove piston connecting rod Most ABC Aluminum piston Brass sleeve hard Chrome plating cylinder liners dont fit crankcase very tightly can removed simply removing frontplate crankshaft possible pushing piston toward top bore Keep gently pushing sleeve will usually come out its stubborn piston doesnt fit tight enough Popsicle stick can inserted exhaust port pushed upward piston get sleeve started out put metal objects exhaust port Use wcod dont use much force piston connecting rod could damaged carbon varnish deposits exist around outside exhaust port sleeve may have removed before sleeve will slip out heavy-duty cleaning like luse automotive carbure tor cleaner auto parts store Use according directions can dont get hands Caution Engine parts made plastic will usually destroyed tf exposed solvent cleaner will remove burned congealed oil carbon varnish paint layers skin other non-metallic materials dipped cleaner will also pit discolor metal parts left too long also smells bad use wellventilated area Flush lots running water sleeve still wont come out Gator RC Products sells set pullers removing stubborn sleeves bearings good investment going very much engine work consist April 1986 41 correctly reassemble engine very Tools such heavy-duty puller homemade wire hook useful engine disas important note non-symmetrical features sembly Use care mar scratch parts stubborn remove disassembiing good example isthe small offset oil hole inthisconrod heat used help remove tight sleeve boiling water torch sleeve crankcase should both placed tops until cool avoid possible warpage split brass ring between tapered flat washer expands nut tightened threaded rod brass ring placed inside top sleeve nut tightened grip sleeve weighted slide hammer rod used knock out sleeve Unfortu nately last report Gator RC sleeve bearing pullers available larger engines pullers come two sizes 60-size sleeves smaller 60-size rear crankshaft bearings bearing puller may also fit some smaller engine sleeves Iron steel sleeves usually fit crank case tighter ABC sleeves almost always harder remove above-mentioned pullers arent available sleeve wont come out normal amount pulling pushing crankcase may heated boiling water aluminum crankcase will expand iron sleeve hopefully make easier remove crankcase should placed upside down top cylinder pan water being heated avoid warpage lay its side Its usually hot enough water comes boil Use oven mitt handle piece 062 music wire can bent hook grasp port sleeve pulling out Dont use hook unless plan replace sleeve may damage cylinder bore top port sleeve removed set crank case sleeve tops cool Caution Dont rest heated sleeve its side intend reuse Bearings crankshaft should checked play binding replace necessary Sometimes thorough cleaning bearings will correct binding caused dirt metal chips bearings can checked rotating crankshaft piston connecting rod removed feeling binding shaft should turn smoothly Usually bearings good free dirt chips after engine cleaned crankshaft oounterweight can turned approximately 900 bottom released will settle bottom position itself Heavy congealed oil frontplate bearings may prevent bearings good Dont assume bearings bad crankshaft wont settle itself good quality ball bearings kept clean theyll usually outlast rest engine cant feel catching binding bearings probably good Some engines designed rear crankshaft bearing supported frontplate fits bore crankcase checking bearings type engine piston connecting rod should removed frontplate reassembled crankcase bearings properly supported 42 Model Aviation Some engines such Supertigre X-60 have pin assure sleeve prop erly oriented aligned crankcase Other engine manufacturers K&B shown ThissleevefortheK&B65ccenglneshows sometimes use notches sleeve relative positions portsshouldyou flange alignment head screws forget reassembling exhaust port right will located higher sleeve intake ports centerand left 1-ln-dia hole 2 x4 makes handy holding fixture several rebuilding length wood dowel used drive operations performed 40-size front bearing out frontplate Wood frontpiate assembly Engines engine nevera metal punch should always used parts will ruined clamping vise avoid damage engine parts wood block used protect crank shaft seating rear bearing re seating will necessary after crash replacing bearings eltherthe crank pin connecting rod rub backplate 1 SCREW 2 GLOW PLUG 3 WASHER 4 HEAD 5 PISTON RING 6 PISTON 7 WRISTPIN 8 CONNECTING ROD 9 SLEEVE 10 CRANKCASE 11 EXHAUST ROTOR 12 BACKPLATE 13 EXHAUST ROTOR LEVER 14 LINK & SPRING 15 LOCKWASHER 16 SCREW 17 CARBURETOR 18O RING 19 CRANKSHAFT 20 REAR BALL BEARING 21 FRONTPLATE 22 FRONT BALL BEARING 23 PROP DRIVE HUB 24 PIN 25 SETSCREW 26 PROP ADAPTER STUD 27 PROP WASHER 28 PROP NUT 29 SETSCREW K&B 40 RC #8011 IllUSTRATION BY WALT & SUZI WILSON dont free up dunk dishwashing water few minutes slosh around try again Some people may agree procedure works bearings free feel smooth dry assembly paper towels blow out water much can oil crankshaft bearings liber ally Marvel Oil favorite light machine oil dont get out water oil steel parts well will rust Alcohol may used washing instead detergent/water detergent much less expensive least effective find impossible get bearings turn freely cleaning proceed follows Remove prop drive hub engines will fall off some cases may stubborn Try holding hub fingers tapping end crankshaft plastic hammer dont have plastic hammer regular hammer may used block wood softer metal such aluminum brass protect end crankshaft Caution Dont hit end crankshaft steel hammer may ruin threads Some engines such older K&B 40 may have drive hub pinned place and/or held place setscrew sure pins setscrews etc removed Small pullers usually available automotive tools sold will get job done else fails older K&B 40 necessary use hammer drift punch crankshaft re cessed hub K&B recommends 2 1 3 6 1 10 K13 r- i1 207 V Iill j2122 29 21 28 25 can test feel shaft bearings bearings become worn excessive ly bore frontplate between bearings will also wear allow fuel blow out through front bearing leakage appears excessive frontplate should also replaced Most engines blow fuel out front bearing some extent little bit blowby no indication excessive wear fact some blowby necessary lubricate front bearing modern engines have ball bearings crankshaft Some older less expensive engines have bronze bushings support crankshaft engine bronze bushing crankshaft shows excessive wear frontplate should replaced worn-out bronze-bushed frontplate integral crankcase would consider abandoning overhaul ing project Replacement crankcase addition other required parts very likely exceed price new engine have old engine bronze bushing badly worn parts no longer available may want investi gate knurling Automotive machine shops knurl worn auto engine valve guides replaceable ream original size may able to crankshaft bushing old model engine brainstorming havent yet occasion try Its possible alternative though really de- assembled frontplate returned terinined restore old engine factory service required cleaning replacing ball bearings hub removed try push out crankshaft must remove the crankshaft through bearings Fre crankshaft bearings quently crankshaft will push right out bearings frontplate dam- though luck usually wont aging anything First try clean doesnt push out try holding frontplate assembled frontplate bearings well tapping end crankshaft as engine parts soaking hot described above Again dont hit end water liquid dishwashing detergent crankshaft directly steel hamAfter few minutes remove frontplate merl doesnt work try supporting assembly solution flush frontplatewithwoodblocks drill hole running lukewarm water Rotate crank- 2 x 4 hole saw slightly larger shaft spin keep flushing bearings crankshaft counterbalance supporting water until feel smooth Continued page 126 April 198643 11 1 N 12N DG DESIGNS Full Body Pilot KIt Lightest Pilot available oLIfelIke vinyl la tex rubber parts Easy assemble finish eBulid either barnstormer sportsman pilot eKit contains pilot head hands boots helmet cap goggles full templates easy instructions eFully positionable & moveable Some simple sewing required Weight Price 116 Scale 2oz* $ 795 1/4 Scale 4 oz $ 995 1/3Scale 6oz $1695 Weight may vary depending material used construction DGA DESIGNS Bust Pilot Kit Weight 1/6Scale 75oz 1/4 Scale 1Soz 1/3 Scale 225 oz Price 595 795 $1495 Lightest bust pilot available eLifelike vinyl latex rubber parts Easy assemble finish Build either barnstormer sportsman pilot Kit contains pilot head helmet cap goggles jacket instructions See dealer order direct Add $100 shipping direct orders Send $100 current catalog Dealers inquiries invited NYS Aesidents add 7 percent sales tax Send Check MO Allow 3 weeks check clearSorry-NO CODs Ei1wu ml Radio Technique/Myers Continued page 123 can perform same kinds tests enough interest exists will spend few columns simple test techniques want send note either MA s publisher George M Myers 70 Froehlich Farm Rd Hicksville NY 11801 Engines/Wilson Continued page 43 frontplate hole try hitting crankshaft little harder cases will job else fails automotive machine shops have press will definitely remove crankshaft Inspect crankshaft scoring grooves discoloration crankpin area around between bearings crankshaft shows roughness wear areas should re placed Again look replacement price before proceeding usually expensive part indication outer races bearings have turning frontplate frontplate should also replaced next challenge removing bearings frontplate front bearing inner race almost always smaller bore frontplate piece wood dowel approximate size bore frontplate can used hammer tap out front bearing rear bearing tight enough stay crankshaft puller used remove drive hub will get off have Gator RC bearing puller removal rear bearing frontplate should no problem Otherwise try heating frontplate pan boiling water Hopefully aluminum frontplate will expand steel bearing outer race allowing removed sufficient room previouslymentioned wire hook may inserted through bearing inner bore help pull out Again use cooking mitt handle frontplate during procedure Reassembly New bearings should gent ly tapped place frontplate plastic hammer Tap around outer race being careful bearing goes bore evenly Dont let bearing get cocked bore crankshaft can used guide get bearing straight sure bearing tapped way bore Keep clean dont want ruin new bearings bearings place oil insert crankshaft prop drive hub K&B 40 must aligned pin holes setscrew match cor responding hole flat crankshaft engines fits tight must driven place hammer Again protect hub counterbalance crankshaft wood blocks ham mering pin hole hub aligned pin hole crankshaft drive roll pin place tighten setscrew other engines drive hub simply slips place Rotate crank shaft few times assure turning freely havent picked up dirt bearings Ring-type pistons sleeves piston rings available separately need purchased matched sets fit piston ring-type engine critical other types unless special racing engine being assembled Some engines have small pin ring groove hold ring given position respect ports carefully check such pin before installing ring piston Some rings such Dykes ring K&B 40 have top bottom cases direction obvious doubt look original piston ring Insert ring cylinder sleeve push little way piston square bore should gap about 0002 inch bore between ends ring no feeler gauge available check see light visible between ends clear ance probably okay engines bore i less no gap visible remove ring file sand ends slightly holding ends together rubbing thin file wet-or-dry sandpaper between File little check often its easy go too far ruin ring ring gap correct clean up ring sure no burrs around ends Carefully spread ring slip over top piston ring groove Align ends pin has Check fit big end connecting rod crankpin should bind does get another connecting rod its unlikely new connecting rod will fit properly Compare new connecting rod old de termine side goes front engine Frequently oil hole side big end fits crankshaft should face specific direction Pistons baffle fence top should have baffle toward intake ports Being sure parts clean facing proper direction oil assemble connecting rod piston inserting wrist pin Most wrist pins have pads ends made Teflon some other relatively soft material pre vent scuffing sleeve Make sure pads place Some wrist pins go way through piston have such pad instance pad obviously end will exposed sleeve area piston pin exposed should aligned ports sleeve Pistons/sleeves ABC engines 126 Model Aviation monthly publication covering International RC Soaring Scene $1 6/yr US Canada & Mexico $24/yr elsewhere via airmail Post Office Box 269 Peterborough NH 03458 justto get Spar 57 Area SOOsqot Weiglst 64 00 loadiug lOooInqft Eagine Requned 4 nyolo 40 2 cycle 2535 Rodio 4 channel loss instructions youll ever buy coos tell put oil money fantartic kit uut u fautastic bou comes hr Want kooro muse ahoot 440 other plaue aud electrouic hits Seud $200 116W 1911s55 PO Hou5L1EJ Hi8gicsoille 540 64077 call us 016 584-7121 order 44 1 00 lrorrdhssg ec Coming 460 NEW lapped iron pistons/sleeves available matched sets no fitting re quired ABC pistons designed fit sleeve tightly top stroke dont alarmed condition discovered heat running en gine expands sleeve piston proper clearance automatic Some ABC engines also use piston rings cases frontplate integral crankcase sleeve removed before piston connecting rod could removed will necessary reassemble piston connecting rod onto crankpin before sleeve inserted Slip piston sleeve bottom sleeve inserted crankcase sounds com plicated reasonable care its difficult engine piston rings must assembled way sleeve usually has tapered bore bottom assist compressing rings Some engines have clearance holes flange top sleeve head screws Some have alignment pin crankcase matches notch flange top sleeve Others have no alignment devices no alignment feature present obvious orienta tion sleeve crankcase may determined follows two-cycle model engine have encountered exhaust ports physi cally located nearer top sleeve intake ports Locate exhaust ports face toward exhaust port crankcase push sleeve place aligning ports crankcase ports go parts clean sleeve will almost always slip place no ringer pressure hangs up way make sure ports lined up place crankcase sleeve upside down clean surface such table push place firmly palm hand bottom crankcase event sleeve will push crankcase reasonable pres sure place sleeve freezer hour may cause sleeve contract enough go crankcase Check time assure ports sleeve aligned ports crankcase over ABC piston rod assembly must sleeve time sleeve assembled crankcase will impossible usually insert ABC piston through top sleeve due tight fit Insert bottom Iron pistons ring-type pistons may assembled sleeve after sleeve crankcase except course frontplate integral crankcase Oil piston wrist pin sleeve generously before assembly ABC iron pis tons simply oriented pushed sleeve proper direction Pistons rings require little effort aligning pin ring groove piston align ring gap pin no pin present ring gap should oriented line ports Push ring groove fingernails gently push piston sleeve may necessary maintain gentle pressure top piston holding ring against top sleeve finger pushing ring groove piston other fingernails its right piston will slip sleeve Align piston bore lower end connecting rod perpendicular centerline crankshaft gasket used place frontplate proper position gasket being reused put exactly same position facing same way removed No sealers necessary Oil crankpin align con necting rod slip frontplate place front crankcase backplate removed support connecting rod finger frontplate crankpin inserted dont go easily find outwhats wrong Dont force everything aproperly aligned will easily slip place Turn crankshaft few times assure everything moves smoothly Insert four frontplate screws snug Tighten little time going first screw directly opposite working around frontplate until tight Dont twist off strip threads crankcase isealuminum threads delicate Check once assure sleeve still aligned ports crankcase install cylinder head Most modern engines dont use head gas kets some use thin shims under head shim engine disassembled sure replaced reassembling Snug screws first tighten little time again going first screw directly opposite working around head Some engines use squish band head some cases specific clearance designated instructions come engine clearance can checked using product called Plastigage available various clearance ranges auto parts stores soft plastic material looks like wire small piece placed top piston will contact squish band flat outer diameter portion head protrudes cylinder before head installed Install head rotate crankshaft couple times remove head Check width mashed Plastigage scale came Dont worry about clearances connecting rod wrist pin allowing piston come closer two-cycle engine running compression combus Continued page 130 April 1986 127 W o hear lot about ocr 440 kit Wish its unique miug desigs 40 four sleoket flyr slum smooth shut just crcs beheor mken see outside loop whot menu Oke half thror / lIe Thurs euchoutmeur Ibis plane after fem ucrubatic maneurets uetves atent frayrd nuds llkr youoe just test flown full wale homehuilt.you feel I.C IOhe yuuoe floated through Now A/ n e iiiS dM/itliVthurs wltos Suuday/llport flying about . LAS 1 e four strokers quiet hut powerful traits ordy odd thdll Joy Ride 4 40 moro thiog eorr built ACE plane kit already know gearifyingit con prIde oucreloes designing moss complote kits offort SAILPLANE LAUNCH EQUIPMENT FOR EVERY S PORT WINCH source QUIET FLIGHT supplies hi-starts accessories electric motors & reducers batteries chutes braided nylon line tow line drums more. VISA MASTERCARD DAVEY 1Pm lE CoRPoRATmN ONE WOOD LANEMALVERNPA19355 215644-6772 SEND SASE FOR INFO Engines/Wilson Continued page 127 tion maintain constant down pressure piston Plastigage mashed out too wide clearance too close thicker shim combination shims shouldbe used Plastigage mashed out wide enough clearance too great thinner shim no shim should used clear ance correct clean off Plastigage piston head reassemble head engine gasket used backplate put place mount backplate engine Tighten screws previously described Rotate crankshaft sure crankpin and/or connecting rod rubbing backplate binding detected tighten propeller crankshaft hold ward doesnt cure problem remove frontplate Using wood block protect crankshaft tap back crankshaft center hammer sure crankshaft rear bearing fully seated forwardmost position Reassemble engine try again crankshaft bearings fully seated should no contact backplate fully-assembled engine turns feels free except case new ABC engine may bind top stroke screw fresh glow plug reassemble carburetor engine 0-ring hold down carburetor against 0-ring tight ening screws nut hold place overhauling procedures have finished engine can broken using same procedures new information article applies generally two-cycle front-intake RC engines conventional constructions Other types engines require somewhat different procedures have better way tasks please write let know Walt Wilson 3000 Persimmon Dr St Charles MO 63301 Addresses companies products mentioned GatorRC Products 3713 Pompano Dr Pensacola FL 32504 K&B Manufacturing 12152 Woodruff Ave Downey CA 90241 Marvel Oil Company Inc Port Ches ter NY 10573 Sealed Power Corp Plastigage 100 Terrace Plaza Muskegon MI 49443 RC Soaring/Pruss Continued page 49 next two years may also thank outgoing officers served two terms four years Warren Plohr LSF/334 Presi dent Larry Jolly LSF/3579 Vice-Presi dent Ken Bates LSF/604 Secretary Cal Sobczynski LSF/2487 Treasurer During 1985 seven gents names added Level V list bringing total up 46 Earle Latimer LSF/31 19 Lansing MI Terry Edmonds LSF/463 Iowa City IA Dale Harber LSF/1880 Yoder IN Charron Smith LSF/4093 Grand MI Richard Ransom LSF/4747 lonia MI Thomas Dickey LSF/3816 Gaithersburg MD Robert Schow LSF/166 Vienna VA Congratulations As column closing out word received Larry Jolly representing USA won first place South Africa flying first International F3H Cross-Country event ever held Larry flying original design Comet Details later article Larry himself Until next month good lift Dan Pruss 131 E Pennington Ln Plainfield IL 60544 RC Electrics/Kopski Continued page 51 lengths nichrome Because nichrome has relatively stable resistance temperature variation copper other conductive wire could used task temperature coefficient copper -many metals around plus % minus 5o per 100 C Thus value shunresistance would vary quite noticeably ambient internal temperature thereby rendering such metals useless purposes later wire used readily available modelers foam-cutting wire RC Modeler PO Box 487 Sierra Madre CA 91024 Cost $225 five-foot length postpaid As received wire measured little over three ohms sug gest confirm yours just sure information given di rectly applicable Ill try give sufficient detail just case can ac commodate somewhat different resist ances few words now before get how-to nittygritty Youll recall discussion last month about ohmmeter function multimeter measure resistance five-foot length nichrome wire set meter selector switch lowest resistance range short test leads together carefully zero ohms adjustment knob until meter pointer rests 0 ohms scale Its often good practice tape meter face gently fingertip sure needle has reached its true resting position connect test leads end nichrome wire Make sure leads make tight contactboth zeroing operation connection What should get 3 33 ohms 130 Model Aviation POW OM RETRIEVER HOBBY HAMMER $Q~ APPROXLENGTH7/Extra Tip INCLUDES$125 ONE STEEL AND ONE BRASS TIP Send check Money Order M &WMODELS PO Box 6627 Huntington Beach CA 92615 Add 150 Post & Hand Rae add 6% tax
Edition: Model Aviation - 1986/04
Page Numbers: 40, 41, 42, 43, 126, 127, 130
MOST iwo-cycle moaei engines can overhauled made perform once did candidates can Identify favorite engine has finally worn itself ragged after years faithful service maybe should consider re building instead putting retirement Parts frequently available procedures straightfor ward bring old friend back life H owto EWalt Wilson Overhaul Two-Cycle Engines MOST OF US have though worn out old engine can hobby number years have engines probably restored perform well have served us faithfully eventually did originally Spare parts usually availjust wore out use Few seem realize able manufacturer its foreign engine US distributor product line Local hobby shops fre quently stock can get needed parts Ideally would replace piston Left Sleeve bearing puilers Gator RC Products make removai easy some stubborn cases theyre necessity Right sleeve pulier features brass ring expands nut tightened compress pius slide hammer provide outward force 40 Model Aviation piston rings wrist pin connecting rod cylinder liner possibly crankshaft bearings complete overhaul Some times cost necessary parts will come close price new engine often old engine can over hauled substantially less Comparative costs should considered before embark ing overhauling project Disassembly cases removal carburetor cylinder head frontplate backplate obvious Caution fore disassembling engine lcok write down identifying features may indicate sides frontplate backplate go up sides cylinder head piston connecting rod go front engine no such features exist mark parts future reference reassembling engine may discover parts have nonsymmetrical features no obvious di rection indicated Gaskets should replaced gasket must reused should care fully removed before submerging parts cleaning solution Note side gasket faces parts screws different lengths note screws go AbouttheAuthor Walt Wilson started build ing solid model airplanes before WW II interest evolved through Control Line Radio Control several years raced tether cars winning scores tro phies held tether car world speed record 15177mph year mid-i 950s Since has very successful racing quarter midget cars stock cars several types stock-bodied drag race cars Along way set several track American Hot Rod Association world records wife Suzi currently very active sports car rallying Wilson has flying RO 15 years Pylon Racing Scale major areas interest has done virtually own engine preparation forms racing through years technical illustrator advanced manage ment currently publications super visor major electronics manufacturer St Louis Some engines have integral frontplates some cases piston connect ing rod cant removed removing cylinder liner engines sufficient clearance just slip off connecting rod crank pin just trying clean up engine after crash journey dirt may able wash wipe away enough foreign matter complete disas sembly However assured thor ough cleanup overhaul faithful power plant must remove piston connecting rod Most ABC Aluminum piston Brass sleeve hard Chrome plating cylinder liners dont fit crankcase very tightly can removed simply removing frontplate crankshaft possible pushing piston toward top bore Keep gently pushing sleeve will usually come out its stubborn piston doesnt fit tight enough Popsicle stick can inserted exhaust port pushed upward piston get sleeve started out put metal objects exhaust port Use wcod dont use much force piston connecting rod could damaged carbon varnish deposits exist around outside exhaust port sleeve may have removed before sleeve will slip out heavy-duty cleaning like luse automotive carbure tor cleaner auto parts store Use according directions can dont get hands Caution Engine parts made plastic will usually destroyed tf exposed solvent cleaner will remove burned congealed oil carbon varnish paint layers skin other non-metallic materials dipped cleaner will also pit discolor metal parts left too long also smells bad use wellventilated area Flush lots running water sleeve still wont come out Gator RC Products sells set pullers removing stubborn sleeves bearings good investment going very much engine work consist April 1986 41 correctly reassemble engine very Tools such heavy-duty puller homemade wire hook useful engine disas important note non-symmetrical features sembly Use care mar scratch parts stubborn remove disassembiing good example isthe small offset oil hole inthisconrod heat used help remove tight sleeve boiling water torch sleeve crankcase should both placed tops until cool avoid possible warpage split brass ring between tapered flat washer expands nut tightened threaded rod brass ring placed inside top sleeve nut tightened grip sleeve weighted slide hammer rod used knock out sleeve Unfortu nately last report Gator RC sleeve bearing pullers available larger engines pullers come two sizes 60-size sleeves smaller 60-size rear crankshaft bearings bearing puller may also fit some smaller engine sleeves Iron steel sleeves usually fit crank case tighter ABC sleeves almost always harder remove above-mentioned pullers arent available sleeve wont come out normal amount pulling pushing crankcase may heated boiling water aluminum crankcase will expand iron sleeve hopefully make easier remove crankcase should placed upside down top cylinder pan water being heated avoid warpage lay its side Its usually hot enough water comes boil Use oven mitt handle piece 062 music wire can bent hook grasp port sleeve pulling out Dont use hook unless plan replace sleeve may damage cylinder bore top port sleeve removed set crank case sleeve tops cool Caution Dont rest heated sleeve its side intend reuse Bearings crankshaft should checked play binding replace necessary Sometimes thorough cleaning bearings will correct binding caused dirt metal chips bearings can checked rotating crankshaft piston connecting rod removed feeling binding shaft should turn smoothly Usually bearings good free dirt chips after engine cleaned crankshaft oounterweight can turned approximately 900 bottom released will settle bottom position itself Heavy congealed oil frontplate bearings may prevent bearings good Dont assume bearings bad crankshaft wont settle itself good quality ball bearings kept clean theyll usually outlast rest engine cant feel catching binding bearings probably good Some engines designed rear crankshaft bearing supported frontplate fits bore crankcase checking bearings type engine piston connecting rod should removed frontplate reassembled crankcase bearings properly supported 42 Model Aviation Some engines such Supertigre X-60 have pin assure sleeve prop erly oriented aligned crankcase Other engine manufacturers K&B shown ThissleevefortheK&B65ccenglneshows sometimes use notches sleeve relative positions portsshouldyou flange alignment head screws forget reassembling exhaust port right will located higher sleeve intake ports centerand left 1-ln-dia hole 2 x4 makes handy holding fixture several rebuilding length wood dowel used drive operations performed 40-size front bearing out frontplate Wood frontpiate assembly Engines engine nevera metal punch should always used parts will ruined clamping vise avoid damage engine parts wood block used protect crank shaft seating rear bearing re seating will necessary after crash replacing bearings eltherthe crank pin connecting rod rub backplate 1 SCREW 2 GLOW PLUG 3 WASHER 4 HEAD 5 PISTON RING 6 PISTON 7 WRISTPIN 8 CONNECTING ROD 9 SLEEVE 10 CRANKCASE 11 EXHAUST ROTOR 12 BACKPLATE 13 EXHAUST ROTOR LEVER 14 LINK & SPRING 15 LOCKWASHER 16 SCREW 17 CARBURETOR 18O RING 19 CRANKSHAFT 20 REAR BALL BEARING 21 FRONTPLATE 22 FRONT BALL BEARING 23 PROP DRIVE HUB 24 PIN 25 SETSCREW 26 PROP ADAPTER STUD 27 PROP WASHER 28 PROP NUT 29 SETSCREW K&B 40 RC #8011 IllUSTRATION BY WALT & SUZI WILSON dont free up dunk dishwashing water few minutes slosh around try again Some people may agree procedure works bearings free feel smooth dry assembly paper towels blow out water much can oil crankshaft bearings liber ally Marvel Oil favorite light machine oil dont get out water oil steel parts well will rust Alcohol may used washing instead detergent/water detergent much less expensive least effective find impossible get bearings turn freely cleaning proceed follows Remove prop drive hub engines will fall off some cases may stubborn Try holding hub fingers tapping end crankshaft plastic hammer dont have plastic hammer regular hammer may used block wood softer metal such aluminum brass protect end crankshaft Caution Dont hit end crankshaft steel hammer may ruin threads Some engines such older K&B 40 may have drive hub pinned place and/or held place setscrew sure pins setscrews etc removed Small pullers usually available automotive tools sold will get job done else fails older K&B 40 necessary use hammer drift punch crankshaft re cessed hub K&B recommends 2 1 3 6 1 10 K13 r- i1 207 V Iill j2122 29 21 28 25 can test feel shaft bearings bearings become worn excessive ly bore frontplate between bearings will also wear allow fuel blow out through front bearing leakage appears excessive frontplate should also replaced Most engines blow fuel out front bearing some extent little bit blowby no indication excessive wear fact some blowby necessary lubricate front bearing modern engines have ball bearings crankshaft Some older less expensive engines have bronze bushings support crankshaft engine bronze bushing crankshaft shows excessive wear frontplate should replaced worn-out bronze-bushed frontplate integral crankcase would consider abandoning overhaul ing project Replacement crankcase addition other required parts very likely exceed price new engine have old engine bronze bushing badly worn parts no longer available may want investi gate knurling Automotive machine shops knurl worn auto engine valve guides replaceable ream original size may able to crankshaft bushing old model engine brainstorming havent yet occasion try Its possible alternative though really de- assembled frontplate returned terinined restore old engine factory service required cleaning replacing ball bearings hub removed try push out crankshaft must remove the crankshaft through bearings Fre crankshaft bearings quently crankshaft will push right out bearings frontplate dam- though luck usually wont aging anything First try clean doesnt push out try holding frontplate assembled frontplate bearings well tapping end crankshaft as engine parts soaking hot described above Again dont hit end water liquid dishwashing detergent crankshaft directly steel hamAfter few minutes remove frontplate merl doesnt work try supporting assembly solution flush frontplatewithwoodblocks drill hole running lukewarm water Rotate crank- 2 x 4 hole saw slightly larger shaft spin keep flushing bearings crankshaft counterbalance supporting water until feel smooth Continued page 126 April 198643 11 1 N 12N DG DESIGNS Full Body Pilot KIt Lightest Pilot available oLIfelIke vinyl la tex rubber parts Easy assemble finish eBulid either barnstormer sportsman pilot eKit contains pilot head hands boots helmet cap goggles full templates easy instructions eFully positionable & moveable Some simple sewing required Weight Price 116 Scale 2oz* $ 795 1/4 Scale 4 oz $ 995 1/3Scale 6oz $1695 Weight may vary depending material used construction DGA DESIGNS Bust Pilot Kit Weight 1/6Scale 75oz 1/4 Scale 1Soz 1/3 Scale 225 oz Price 595 795 $1495 Lightest bust pilot available eLifelike vinyl latex rubber parts Easy assemble finish Build either barnstormer sportsman pilot Kit contains pilot head helmet cap goggles jacket instructions See dealer order direct Add $100 shipping direct orders Send $100 current catalog Dealers inquiries invited NYS Aesidents add 7 percent sales tax Send Check MO Allow 3 weeks check clearSorry-NO CODs Ei1wu ml Radio Technique/Myers Continued page 123 can perform same kinds tests enough interest exists will spend few columns simple test techniques want send note either MA s publisher George M Myers 70 Froehlich Farm Rd Hicksville NY 11801 Engines/Wilson Continued page 43 frontplate hole try hitting crankshaft little harder cases will job else fails automotive machine shops have press will definitely remove crankshaft Inspect crankshaft scoring grooves discoloration crankpin area around between bearings crankshaft shows roughness wear areas should re placed Again look replacement price before proceeding usually expensive part indication outer races bearings have turning frontplate frontplate should also replaced next challenge removing bearings frontplate front bearing inner race almost always smaller bore frontplate piece wood dowel approximate size bore frontplate can used hammer tap out front bearing rear bearing tight enough stay crankshaft puller used remove drive hub will get off have Gator RC bearing puller removal rear bearing frontplate should no problem Otherwise try heating frontplate pan boiling water Hopefully aluminum frontplate will expand steel bearing outer race allowing removed sufficient room previouslymentioned wire hook may inserted through bearing inner bore help pull out Again use cooking mitt handle frontplate during procedure Reassembly New bearings should gent ly tapped place frontplate plastic hammer Tap around outer race being careful bearing goes bore evenly Dont let bearing get cocked bore crankshaft can used guide get bearing straight sure bearing tapped way bore Keep clean dont want ruin new bearings bearings place oil insert crankshaft prop drive hub K&B 40 must aligned pin holes setscrew match cor responding hole flat crankshaft engines fits tight must driven place hammer Again protect hub counterbalance crankshaft wood blocks ham mering pin hole hub aligned pin hole crankshaft drive roll pin place tighten setscrew other engines drive hub simply slips place Rotate crank shaft few times assure turning freely havent picked up dirt bearings Ring-type pistons sleeves piston rings available separately need purchased matched sets fit piston ring-type engine critical other types unless special racing engine being assembled Some engines have small pin ring groove hold ring given position respect ports carefully check such pin before installing ring piston Some rings such Dykes ring K&B 40 have top bottom cases direction obvious doubt look original piston ring Insert ring cylinder sleeve push little way piston square bore should gap about 0002 inch bore between ends ring no feeler gauge available check see light visible between ends clear ance probably okay engines bore i less no gap visible remove ring file sand ends slightly holding ends together rubbing thin file wet-or-dry sandpaper between File little check often its easy go too far ruin ring ring gap correct clean up ring sure no burrs around ends Carefully spread ring slip over top piston ring groove Align ends pin has Check fit big end connecting rod crankpin should bind does get another connecting rod its unlikely new connecting rod will fit properly Compare new connecting rod old de termine side goes front engine Frequently oil hole side big end fits crankshaft should face specific direction Pistons baffle fence top should have baffle toward intake ports Being sure parts clean facing proper direction oil assemble connecting rod piston inserting wrist pin Most wrist pins have pads ends made Teflon some other relatively soft material pre vent scuffing sleeve Make sure pads place Some wrist pins go way through piston have such pad instance pad obviously end will exposed sleeve area piston pin exposed should aligned ports sleeve Pistons/sleeves ABC engines 126 Model Aviation monthly publication covering International RC Soaring Scene $1 6/yr US Canada & Mexico $24/yr elsewhere via airmail Post Office Box 269 Peterborough NH 03458 justto get Spar 57 Area SOOsqot Weiglst 64 00 loadiug lOooInqft Eagine Requned 4 nyolo 40 2 cycle 2535 Rodio 4 channel loss instructions youll ever buy coos tell put oil money fantartic kit uut u fautastic bou comes hr Want kooro muse ahoot 440 other plaue aud electrouic hits Seud $200 116W 1911s55 PO Hou5L1EJ Hi8gicsoille 540 64077 call us 016 584-7121 order 44 1 00 lrorrdhssg ec Coming 460 NEW lapped iron pistons/sleeves available matched sets no fitting re quired ABC pistons designed fit sleeve tightly top stroke dont alarmed condition discovered heat running en gine expands sleeve piston proper clearance automatic Some ABC engines also use piston rings cases frontplate integral crankcase sleeve removed before piston connecting rod could removed will necessary reassemble piston connecting rod onto crankpin before sleeve inserted Slip piston sleeve bottom sleeve inserted crankcase sounds com plicated reasonable care its difficult engine piston rings must assembled way sleeve usually has tapered bore bottom assist compressing rings Some engines have clearance holes flange top sleeve head screws Some have alignment pin crankcase matches notch flange top sleeve Others have no alignment devices no alignment feature present obvious orienta tion sleeve crankcase may determined follows two-cycle model engine have encountered exhaust ports physi cally located nearer top sleeve intake ports Locate exhaust ports face toward exhaust port crankcase push sleeve place aligning ports crankcase ports go parts clean sleeve will almost always slip place no ringer pressure hangs up way make sure ports lined up place crankcase sleeve upside down clean surface such table push place firmly palm hand bottom crankcase event sleeve will push crankcase reasonable pres sure place sleeve freezer hour may cause sleeve contract enough go crankcase Check time assure ports sleeve aligned ports crankcase over ABC piston rod assembly must sleeve time sleeve assembled crankcase will impossible usually insert ABC piston through top sleeve due tight fit Insert bottom Iron pistons ring-type pistons may assembled sleeve after sleeve crankcase except course frontplate integral crankcase Oil piston wrist pin sleeve generously before assembly ABC iron pis tons simply oriented pushed sleeve proper direction Pistons rings require little effort aligning pin ring groove piston align ring gap pin no pin present ring gap should oriented line ports Push ring groove fingernails gently push piston sleeve may necessary maintain gentle pressure top piston holding ring against top sleeve finger pushing ring groove piston other fingernails its right piston will slip sleeve Align piston bore lower end connecting rod perpendicular centerline crankshaft gasket used place frontplate proper position gasket being reused put exactly same position facing same way removed No sealers necessary Oil crankpin align con necting rod slip frontplate place front crankcase backplate removed support connecting rod finger frontplate crankpin inserted dont go easily find outwhats wrong Dont force everything aproperly aligned will easily slip place Turn crankshaft few times assure everything moves smoothly Insert four frontplate screws snug Tighten little time going first screw directly opposite working around frontplate until tight Dont twist off strip threads crankcase isealuminum threads delicate Check once assure sleeve still aligned ports crankcase install cylinder head Most modern engines dont use head gas kets some use thin shims under head shim engine disassembled sure replaced reassembling Snug screws first tighten little time again going first screw directly opposite working around head Some engines use squish band head some cases specific clearance designated instructions come engine clearance can checked using product called Plastigage available various clearance ranges auto parts stores soft plastic material looks like wire small piece placed top piston will contact squish band flat outer diameter portion head protrudes cylinder before head installed Install head rotate crankshaft couple times remove head Check width mashed Plastigage scale came Dont worry about clearances connecting rod wrist pin allowing piston come closer two-cycle engine running compression combus Continued page 130 April 1986 127 W o hear lot about ocr 440 kit Wish its unique miug desigs 40 four sleoket flyr slum smooth shut just crcs beheor mken see outside loop whot menu Oke half thror / lIe Thurs euchoutmeur Ibis plane after fem ucrubatic maneurets uetves atent frayrd nuds llkr youoe just test flown full wale homehuilt.you feel I.C IOhe yuuoe floated through Now A/ n e iiiS dM/itliVthurs wltos Suuday/llport flying about . LAS 1 e four strokers quiet hut powerful traits ordy odd thdll Joy Ride 4 40 moro thiog eorr built ACE plane kit already know gearifyingit con prIde oucreloes designing moss complote kits offort SAILPLANE LAUNCH EQUIPMENT FOR EVERY S PORT WINCH source QUIET FLIGHT supplies hi-starts accessories electric motors & reducers batteries chutes braided nylon line tow line drums more. VISA MASTERCARD DAVEY 1Pm lE CoRPoRATmN ONE WOOD LANEMALVERNPA19355 215644-6772 SEND SASE FOR INFO Engines/Wilson Continued page 127 tion maintain constant down pressure piston Plastigage mashed out too wide clearance too close thicker shim combination shims shouldbe used Plastigage mashed out wide enough clearance too great thinner shim no shim should used clear ance correct clean off Plastigage piston head reassemble head engine gasket used backplate put place mount backplate engine Tighten screws previously described Rotate crankshaft sure crankpin and/or connecting rod rubbing backplate binding detected tighten propeller crankshaft hold ward doesnt cure problem remove frontplate Using wood block protect crankshaft tap back crankshaft center hammer sure crankshaft rear bearing fully seated forwardmost position Reassemble engine try again crankshaft bearings fully seated should no contact backplate fully-assembled engine turns feels free except case new ABC engine may bind top stroke screw fresh glow plug reassemble carburetor engine 0-ring hold down carburetor against 0-ring tight ening screws nut hold place overhauling procedures have finished engine can broken using same procedures new information article applies generally two-cycle front-intake RC engines conventional constructions Other types engines require somewhat different procedures have better way tasks please write let know Walt Wilson 3000 Persimmon Dr St Charles MO 63301 Addresses companies products mentioned GatorRC Products 3713 Pompano Dr Pensacola FL 32504 K&B Manufacturing 12152 Woodruff Ave Downey CA 90241 Marvel Oil Company Inc Port Ches ter NY 10573 Sealed Power Corp Plastigage 100 Terrace Plaza Muskegon MI 49443 RC Soaring/Pruss Continued page 49 next two years may also thank outgoing officers served two terms four years Warren Plohr LSF/334 Presi dent Larry Jolly LSF/3579 Vice-Presi dent Ken Bates LSF/604 Secretary Cal Sobczynski LSF/2487 Treasurer During 1985 seven gents names added Level V list bringing total up 46 Earle Latimer LSF/31 19 Lansing MI Terry Edmonds LSF/463 Iowa City IA Dale Harber LSF/1880 Yoder IN Charron Smith LSF/4093 Grand MI Richard Ransom LSF/4747 lonia MI Thomas Dickey LSF/3816 Gaithersburg MD Robert Schow LSF/166 Vienna VA Congratulations As column closing out word received Larry Jolly representing USA won first place South Africa flying first International F3H Cross-Country event ever held Larry flying original design Comet Details later article Larry himself Until next month good lift Dan Pruss 131 E Pennington Ln Plainfield IL 60544 RC Electrics/Kopski Continued page 51 lengths nichrome Because nichrome has relatively stable resistance temperature variation copper other conductive wire could used task temperature coefficient copper -many metals around plus % minus 5o per 100 C Thus value shunresistance would vary quite noticeably ambient internal temperature thereby rendering such metals useless purposes later wire used readily available modelers foam-cutting wire RC Modeler PO Box 487 Sierra Madre CA 91024 Cost $225 five-foot length postpaid As received wire measured little over three ohms sug gest confirm yours just sure information given di rectly applicable Ill try give sufficient detail just case can ac commodate somewhat different resist ances few words now before get how-to nittygritty Youll recall discussion last month about ohmmeter function multimeter measure resistance five-foot length nichrome wire set meter selector switch lowest resistance range short test leads together carefully zero ohms adjustment knob until meter pointer rests 0 ohms scale Its often good practice tape meter face gently fingertip sure needle has reached its true resting position connect test leads end nichrome wire Make sure leads make tight contactboth zeroing operation connection What should get 3 33 ohms 130 Model Aviation POW OM RETRIEVER HOBBY HAMMER $Q~ APPROXLENGTH7/Extra Tip INCLUDES$125 ONE STEEL AND ONE BRASS TIP Send check Money Order M &WMODELS PO Box 6627 Huntington Beach CA 92615 Add 150 Post & Hand Rae add 6% tax
Edition: Model Aviation - 1986/04
Page Numbers: 40, 41, 42, 43, 126, 127, 130
MOST iwo-cycle moaei engines can overhauled made perform once did candidates can Identify favorite engine has finally worn itself ragged after years faithful service maybe should consider re building instead putting retirement Parts frequently available procedures straightfor ward bring old friend back life H owto EWalt Wilson Overhaul Two-Cycle Engines MOST OF US have though worn out old engine can hobby number years have engines probably restored perform well have served us faithfully eventually did originally Spare parts usually availjust wore out use Few seem realize able manufacturer its foreign engine US distributor product line Local hobby shops fre quently stock can get needed parts Ideally would replace piston Left Sleeve bearing puilers Gator RC Products make removai easy some stubborn cases theyre necessity Right sleeve pulier features brass ring expands nut tightened compress pius slide hammer provide outward force 40 Model Aviation piston rings wrist pin connecting rod cylinder liner possibly crankshaft bearings complete overhaul Some times cost necessary parts will come close price new engine often old engine can over hauled substantially less Comparative costs should considered before embark ing overhauling project Disassembly cases removal carburetor cylinder head frontplate backplate obvious Caution fore disassembling engine lcok write down identifying features may indicate sides frontplate backplate go up sides cylinder head piston connecting rod go front engine no such features exist mark parts future reference reassembling engine may discover parts have nonsymmetrical features no obvious di rection indicated Gaskets should replaced gasket must reused should care fully removed before submerging parts cleaning solution Note side gasket faces parts screws different lengths note screws go AbouttheAuthor Walt Wilson started build ing solid model airplanes before WW II interest evolved through Control Line Radio Control several years raced tether cars winning scores tro phies held tether car world speed record 15177mph year mid-i 950s Since has very successful racing quarter midget cars stock cars several types stock-bodied drag race cars Along way set several track American Hot Rod Association world records wife Suzi currently very active sports car rallying Wilson has flying RO 15 years Pylon Racing Scale major areas interest has done virtually own engine preparation forms racing through years technical illustrator advanced manage ment currently publications super visor major electronics manufacturer St Louis Some engines have integral frontplates some cases piston connect ing rod cant removed removing cylinder liner engines sufficient clearance just slip off connecting rod crank pin just trying clean up engine after crash journey dirt may able wash wipe away enough foreign matter complete disas sembly However assured thor ough cleanup overhaul faithful power plant must remove piston connecting rod Most ABC Aluminum piston Brass sleeve hard Chrome plating cylinder liners dont fit crankcase very tightly can removed simply removing frontplate crankshaft possible pushing piston toward top bore Keep gently pushing sleeve will usually come out its stubborn piston doesnt fit tight enough Popsicle stick can inserted exhaust port pushed upward piston get sleeve started out put metal objects exhaust port Use wcod dont use much force piston connecting rod could damaged carbon varnish deposits exist around outside exhaust port sleeve may have removed before sleeve will slip out heavy-duty cleaning like luse automotive carbure tor cleaner auto parts store Use according directions can dont get hands Caution Engine parts made plastic will usually destroyed tf exposed solvent cleaner will remove burned congealed oil carbon varnish paint layers skin other non-metallic materials dipped cleaner will also pit discolor metal parts left too long also smells bad use wellventilated area Flush lots running water sleeve still wont come out Gator RC Products sells set pullers removing stubborn sleeves bearings good investment going very much engine work consist April 1986 41 correctly reassemble engine very Tools such heavy-duty puller homemade wire hook useful engine disas important note non-symmetrical features sembly Use care mar scratch parts stubborn remove disassembiing good example isthe small offset oil hole inthisconrod heat used help remove tight sleeve boiling water torch sleeve crankcase should both placed tops until cool avoid possible warpage split brass ring between tapered flat washer expands nut tightened threaded rod brass ring placed inside top sleeve nut tightened grip sleeve weighted slide hammer rod used knock out sleeve Unfortu nately last report Gator RC sleeve bearing pullers available larger engines pullers come two sizes 60-size sleeves smaller 60-size rear crankshaft bearings bearing puller may also fit some smaller engine sleeves Iron steel sleeves usually fit crank case tighter ABC sleeves almost always harder remove above-mentioned pullers arent available sleeve wont come out normal amount pulling pushing crankcase may heated boiling water aluminum crankcase will expand iron sleeve hopefully make easier remove crankcase should placed upside down top cylinder pan water being heated avoid warpage lay its side Its usually hot enough water comes boil Use oven mitt handle piece 062 music wire can bent hook grasp port sleeve pulling out Dont use hook unless plan replace sleeve may damage cylinder bore top port sleeve removed set crank case sleeve tops cool Caution Dont rest heated sleeve its side intend reuse Bearings crankshaft should checked play binding replace necessary Sometimes thorough cleaning bearings will correct binding caused dirt metal chips bearings can checked rotating crankshaft piston connecting rod removed feeling binding shaft should turn smoothly Usually bearings good free dirt chips after engine cleaned crankshaft oounterweight can turned approximately 900 bottom released will settle bottom position itself Heavy congealed oil frontplate bearings may prevent bearings good Dont assume bearings bad crankshaft wont settle itself good quality ball bearings kept clean theyll usually outlast rest engine cant feel catching binding bearings probably good Some engines designed rear crankshaft bearing supported frontplate fits bore crankcase checking bearings type engine piston connecting rod should removed frontplate reassembled crankcase bearings properly supported 42 Model Aviation Some engines such Supertigre X-60 have pin assure sleeve prop erly oriented aligned crankcase Other engine manufacturers K&B shown ThissleevefortheK&B65ccenglneshows sometimes use notches sleeve relative positions portsshouldyou flange alignment head screws forget reassembling exhaust port right will located higher sleeve intake ports centerand left 1-ln-dia hole 2 x4 makes handy holding fixture several rebuilding length wood dowel used drive operations performed 40-size front bearing out frontplate Wood frontpiate assembly Engines engine nevera metal punch should always used parts will ruined clamping vise avoid damage engine parts wood block used protect crank shaft seating rear bearing re seating will necessary after crash replacing bearings eltherthe crank pin connecting rod rub backplate 1 SCREW 2 GLOW PLUG 3 WASHER 4 HEAD 5 PISTON RING 6 PISTON 7 WRISTPIN 8 CONNECTING ROD 9 SLEEVE 10 CRANKCASE 11 EXHAUST ROTOR 12 BACKPLATE 13 EXHAUST ROTOR LEVER 14 LINK & SPRING 15 LOCKWASHER 16 SCREW 17 CARBURETOR 18O RING 19 CRANKSHAFT 20 REAR BALL BEARING 21 FRONTPLATE 22 FRONT BALL BEARING 23 PROP DRIVE HUB 24 PIN 25 SETSCREW 26 PROP ADAPTER STUD 27 PROP WASHER 28 PROP NUT 29 SETSCREW K&B 40 RC #8011 IllUSTRATION BY WALT & SUZI WILSON dont free up dunk dishwashing water few minutes slosh around try again Some people may agree procedure works bearings free feel smooth dry assembly paper towels blow out water much can oil crankshaft bearings liber ally Marvel Oil favorite light machine oil dont get out water oil steel parts well will rust Alcohol may used washing instead detergent/water detergent much less expensive least effective find impossible get bearings turn freely cleaning proceed follows Remove prop drive hub engines will fall off some cases may stubborn Try holding hub fingers tapping end crankshaft plastic hammer dont have plastic hammer regular hammer may used block wood softer metal such aluminum brass protect end crankshaft Caution Dont hit end crankshaft steel hammer may ruin threads Some engines such older K&B 40 may have drive hub pinned place and/or held place setscrew sure pins setscrews etc removed Small pullers usually available automotive tools sold will get job done else fails older K&B 40 necessary use hammer drift punch crankshaft re cessed hub K&B recommends 2 1 3 6 1 10 K13 r- i1 207 V Iill j2122 29 21 28 25 can test feel shaft bearings bearings become worn excessive ly bore frontplate between bearings will also wear allow fuel blow out through front bearing leakage appears excessive frontplate should also replaced Most engines blow fuel out front bearing some extent little bit blowby no indication excessive wear fact some blowby necessary lubricate front bearing modern engines have ball bearings crankshaft Some older less expensive engines have bronze bushings support crankshaft engine bronze bushing crankshaft shows excessive wear frontplate should replaced worn-out bronze-bushed frontplate integral crankcase would consider abandoning overhaul ing project Replacement crankcase addition other required parts very likely exceed price new engine have old engine bronze bushing badly worn parts no longer available may want investi gate knurling Automotive machine shops knurl worn auto engine valve guides replaceable ream original size may able to crankshaft bushing old model engine brainstorming havent yet occasion try Its possible alternative though really de- assembled frontplate returned terinined restore old engine factory service required cleaning replacing ball bearings hub removed try push out crankshaft must remove the crankshaft through bearings Fre crankshaft bearings quently crankshaft will push right out bearings frontplate dam- though luck usually wont aging anything First try clean doesnt push out try holding frontplate assembled frontplate bearings well tapping end crankshaft as engine parts soaking hot described above Again dont hit end water liquid dishwashing detergent crankshaft directly steel hamAfter few minutes remove frontplate merl doesnt work try supporting assembly solution flush frontplatewithwoodblocks drill hole running lukewarm water Rotate crank- 2 x 4 hole saw slightly larger shaft spin keep flushing bearings crankshaft counterbalance supporting water until feel smooth Continued page 126 April 198643 11 1 N 12N DG DESIGNS Full Body Pilot KIt Lightest Pilot available oLIfelIke vinyl la tex rubber parts Easy assemble finish eBulid either barnstormer sportsman pilot eKit contains pilot head hands boots helmet cap goggles full templates easy instructions eFully positionable & moveable Some simple sewing required Weight Price 116 Scale 2oz* $ 795 1/4 Scale 4 oz $ 995 1/3Scale 6oz $1695 Weight may vary depending material used construction DGA DESIGNS Bust Pilot Kit Weight 1/6Scale 75oz 1/4 Scale 1Soz 1/3 Scale 225 oz Price 595 795 $1495 Lightest bust pilot available eLifelike vinyl latex rubber parts Easy assemble finish Build either barnstormer sportsman pilot Kit contains pilot head helmet cap goggles jacket instructions See dealer order direct Add $100 shipping direct orders Send $100 current catalog Dealers inquiries invited NYS Aesidents add 7 percent sales tax Send Check MO Allow 3 weeks check clearSorry-NO CODs Ei1wu ml Radio Technique/Myers Continued page 123 can perform same kinds tests enough interest exists will spend few columns simple test techniques want send note either MA s publisher George M Myers 70 Froehlich Farm Rd Hicksville NY 11801 Engines/Wilson Continued page 43 frontplate hole try hitting crankshaft little harder cases will job else fails automotive machine shops have press will definitely remove crankshaft Inspect crankshaft scoring grooves discoloration crankpin area around between bearings crankshaft shows roughness wear areas should re placed Again look replacement price before proceeding usually expensive part indication outer races bearings have turning frontplate frontplate should also replaced next challenge removing bearings frontplate front bearing inner race almost always smaller bore frontplate piece wood dowel approximate size bore frontplate can used hammer tap out front bearing rear bearing tight enough stay crankshaft puller used remove drive hub will get off have Gator RC bearing puller removal rear bearing frontplate should no problem Otherwise try heating frontplate pan boiling water Hopefully aluminum frontplate will expand steel bearing outer race allowing removed sufficient room previouslymentioned wire hook may inserted through bearing inner bore help pull out Again use cooking mitt handle frontplate during procedure Reassembly New bearings should gent ly tapped place frontplate plastic hammer Tap around outer race being careful bearing goes bore evenly Dont let bearing get cocked bore crankshaft can used guide get bearing straight sure bearing tapped way bore Keep clean dont want ruin new bearings bearings place oil insert crankshaft prop drive hub K&B 40 must aligned pin holes setscrew match cor responding hole flat crankshaft engines fits tight must driven place hammer Again protect hub counterbalance crankshaft wood blocks ham mering pin hole hub aligned pin hole crankshaft drive roll pin place tighten setscrew other engines drive hub simply slips place Rotate crank shaft few times assure turning freely havent picked up dirt bearings Ring-type pistons sleeves piston rings available separately need purchased matched sets fit piston ring-type engine critical other types unless special racing engine being assembled Some engines have small pin ring groove hold ring given position respect ports carefully check such pin before installing ring piston Some rings such Dykes ring K&B 40 have top bottom cases direction obvious doubt look original piston ring Insert ring cylinder sleeve push little way piston square bore should gap about 0002 inch bore between ends ring no feeler gauge available check see light visible between ends clear ance probably okay engines bore i less no gap visible remove ring file sand ends slightly holding ends together rubbing thin file wet-or-dry sandpaper between File little check often its easy go too far ruin ring ring gap correct clean up ring sure no burrs around ends Carefully spread ring slip over top piston ring groove Align ends pin has Check fit big end connecting rod crankpin should bind does get another connecting rod its unlikely new connecting rod will fit properly Compare new connecting rod old de termine side goes front engine Frequently oil hole side big end fits crankshaft should face specific direction Pistons baffle fence top should have baffle toward intake ports Being sure parts clean facing proper direction oil assemble connecting rod piston inserting wrist pin Most wrist pins have pads ends made Teflon some other relatively soft material pre vent scuffing sleeve Make sure pads place Some wrist pins go way through piston have such pad instance pad obviously end will exposed sleeve area piston pin exposed should aligned ports sleeve Pistons/sleeves ABC engines 126 Model Aviation monthly publication covering International RC Soaring Scene $1 6/yr US Canada & Mexico $24/yr elsewhere via airmail Post Office Box 269 Peterborough NH 03458 justto get Spar 57 Area SOOsqot Weiglst 64 00 loadiug lOooInqft Eagine Requned 4 nyolo 40 2 cycle 2535 Rodio 4 channel loss instructions youll ever buy coos tell put oil money fantartic kit uut u fautastic bou comes hr Want kooro muse ahoot 440 other plaue aud electrouic hits Seud $200 116W 1911s55 PO Hou5L1EJ Hi8gicsoille 540 64077 call us 016 584-7121 order 44 1 00 lrorrdhssg ec Coming 460 NEW lapped iron pistons/sleeves available matched sets no fitting re quired ABC pistons designed fit sleeve tightly top stroke dont alarmed condition discovered heat running en gine expands sleeve piston proper clearance automatic Some ABC engines also use piston rings cases frontplate integral crankcase sleeve removed before piston connecting rod could removed will necessary reassemble piston connecting rod onto crankpin before sleeve inserted Slip piston sleeve bottom sleeve inserted crankcase sounds com plicated reasonable care its difficult engine piston rings must assembled way sleeve usually has tapered bore bottom assist compressing rings Some engines have clearance holes flange top sleeve head screws Some have alignment pin crankcase matches notch flange top sleeve Others have no alignment devices no alignment feature present obvious orienta tion sleeve crankcase may determined follows two-cycle model engine have encountered exhaust ports physi cally located nearer top sleeve intake ports Locate exhaust ports face toward exhaust port crankcase push sleeve place aligning ports crankcase ports go parts clean sleeve will almost always slip place no ringer pressure hangs up way make sure ports lined up place crankcase sleeve upside down clean surface such table push place firmly palm hand bottom crankcase event sleeve will push crankcase reasonable pres sure place sleeve freezer hour may cause sleeve contract enough go crankcase Check time assure ports sleeve aligned ports crankcase over ABC piston rod assembly must sleeve time sleeve assembled crankcase will impossible usually insert ABC piston through top sleeve due tight fit Insert bottom Iron pistons ring-type pistons may assembled sleeve after sleeve crankcase except course frontplate integral crankcase Oil piston wrist pin sleeve generously before assembly ABC iron pis tons simply oriented pushed sleeve proper direction Pistons rings require little effort aligning pin ring groove piston align ring gap pin no pin present ring gap should oriented line ports Push ring groove fingernails gently push piston sleeve may necessary maintain gentle pressure top piston holding ring against top sleeve finger pushing ring groove piston other fingernails its right piston will slip sleeve Align piston bore lower end connecting rod perpendicular centerline crankshaft gasket used place frontplate proper position gasket being reused put exactly same position facing same way removed No sealers necessary Oil crankpin align con necting rod slip frontplate place front crankcase backplate removed support connecting rod finger frontplate crankpin inserted dont go easily find outwhats wrong Dont force everything aproperly aligned will easily slip place Turn crankshaft few times assure everything moves smoothly Insert four frontplate screws snug Tighten little time going first screw directly opposite working around frontplate until tight Dont twist off strip threads crankcase isealuminum threads delicate Check once assure sleeve still aligned ports crankcase install cylinder head Most modern engines dont use head gas kets some use thin shims under head shim engine disassembled sure replaced reassembling Snug screws first tighten little time again going first screw directly opposite working around head Some engines use squish band head some cases specific clearance designated instructions come engine clearance can checked using product called Plastigage available various clearance ranges auto parts stores soft plastic material looks like wire small piece placed top piston will contact squish band flat outer diameter portion head protrudes cylinder before head installed Install head rotate crankshaft couple times remove head Check width mashed Plastigage scale came Dont worry about clearances connecting rod wrist pin allowing piston come closer two-cycle engine running compression combus Continued page 130 April 1986 127 W o hear lot about ocr 440 kit Wish its unique miug desigs 40 four sleoket flyr slum smooth shut just crcs beheor mken see outside loop whot menu Oke half thror / lIe Thurs euchoutmeur Ibis plane after fem ucrubatic maneurets uetves atent frayrd nuds llkr youoe just test flown full wale homehuilt.you feel I.C IOhe yuuoe floated through Now A/ n e iiiS dM/itliVthurs wltos Suuday/llport flying about . LAS 1 e four strokers quiet hut powerful traits ordy odd thdll Joy Ride 4 40 moro thiog eorr built ACE plane kit already know gearifyingit con prIde oucreloes designing moss complote kits offort SAILPLANE LAUNCH EQUIPMENT FOR EVERY S PORT WINCH source QUIET FLIGHT supplies hi-starts accessories electric motors & reducers batteries chutes braided nylon line tow line drums more. VISA MASTERCARD DAVEY 1Pm lE CoRPoRATmN ONE WOOD LANEMALVERNPA19355 215644-6772 SEND SASE FOR INFO Engines/Wilson Continued page 127 tion maintain constant down pressure piston Plastigage mashed out too wide clearance too close thicker shim combination shims shouldbe used Plastigage mashed out wide enough clearance too great thinner shim no shim should used clear ance correct clean off Plastigage piston head reassemble head engine gasket used backplate put place mount backplate engine Tighten screws previously described Rotate crankshaft sure crankpin and/or connecting rod rubbing backplate binding detected tighten propeller crankshaft hold ward doesnt cure problem remove frontplate Using wood block protect crankshaft tap back crankshaft center hammer sure crankshaft rear bearing fully seated forwardmost position Reassemble engine try again crankshaft bearings fully seated should no contact backplate fully-assembled engine turns feels free except case new ABC engine may bind top stroke screw fresh glow plug reassemble carburetor engine 0-ring hold down carburetor against 0-ring tight ening screws nut hold place overhauling procedures have finished engine can broken using same procedures new information article applies generally two-cycle front-intake RC engines conventional constructions Other types engines require somewhat different procedures have better way tasks please write let know Walt Wilson 3000 Persimmon Dr St Charles MO 63301 Addresses companies products mentioned GatorRC Products 3713 Pompano Dr Pensacola FL 32504 K&B Manufacturing 12152 Woodruff Ave Downey CA 90241 Marvel Oil Company Inc Port Ches ter NY 10573 Sealed Power Corp Plastigage 100 Terrace Plaza Muskegon MI 49443 RC Soaring/Pruss Continued page 49 next two years may also thank outgoing officers served two terms four years Warren Plohr LSF/334 Presi dent Larry Jolly LSF/3579 Vice-Presi dent Ken Bates LSF/604 Secretary Cal Sobczynski LSF/2487 Treasurer During 1985 seven gents names added Level V list bringing total up 46 Earle Latimer LSF/31 19 Lansing MI Terry Edmonds LSF/463 Iowa City IA Dale Harber LSF/1880 Yoder IN Charron Smith LSF/4093 Grand MI Richard Ransom LSF/4747 lonia MI Thomas Dickey LSF/3816 Gaithersburg MD Robert Schow LSF/166 Vienna VA Congratulations As column closing out word received Larry Jolly representing USA won first place South Africa flying first International F3H Cross-Country event ever held Larry flying original design Comet Details later article Larry himself Until next month good lift Dan Pruss 131 E Pennington Ln Plainfield IL 60544 RC Electrics/Kopski Continued page 51 lengths nichrome Because nichrome has relatively stable resistance temperature variation copper other conductive wire could used task temperature coefficient copper -many metals around plus % minus 5o per 100 C Thus value shunresistance would vary quite noticeably ambient internal temperature thereby rendering such metals useless purposes later wire used readily available modelers foam-cutting wire RC Modeler PO Box 487 Sierra Madre CA 91024 Cost $225 five-foot length postpaid As received wire measured little over three ohms sug gest confirm yours just sure information given di rectly applicable Ill try give sufficient detail just case can ac commodate somewhat different resist ances few words now before get how-to nittygritty Youll recall discussion last month about ohmmeter function multimeter measure resistance five-foot length nichrome wire set meter selector switch lowest resistance range short test leads together carefully zero ohms adjustment knob until meter pointer rests 0 ohms scale Its often good practice tape meter face gently fingertip sure needle has reached its true resting position connect test leads end nichrome wire Make sure leads make tight contactboth zeroing operation connection What should get 3 33 ohms 130 Model Aviation POW OM RETRIEVER HOBBY HAMMER $Q~ APPROXLENGTH7/Extra Tip INCLUDES$125 ONE STEEL AND ONE BRASS TIP Send check Money Order M &WMODELS PO Box 6627 Huntington Beach CA 92615 Add 150 Post & Hand Rae add 6% tax
Edition: Model Aviation - 1986/04
Page Numbers: 40, 41, 42, 43, 126, 127, 130
MOST iwo-cycle moaei engines can overhauled made perform once did candidates can Identify favorite engine has finally worn itself ragged after years faithful service maybe should consider re building instead putting retirement Parts frequently available procedures straightfor ward bring old friend back life H owto EWalt Wilson Overhaul Two-Cycle Engines MOST OF US have though worn out old engine can hobby number years have engines probably restored perform well have served us faithfully eventually did originally Spare parts usually availjust wore out use Few seem realize able manufacturer its foreign engine US distributor product line Local hobby shops fre quently stock can get needed parts Ideally would replace piston Left Sleeve bearing puilers Gator RC Products make removai easy some stubborn cases theyre necessity Right sleeve pulier features brass ring expands nut tightened compress pius slide hammer provide outward force 40 Model Aviation piston rings wrist pin connecting rod cylinder liner possibly crankshaft bearings complete overhaul Some times cost necessary parts will come close price new engine often old engine can over hauled substantially less Comparative costs should considered before embark ing overhauling project Disassembly cases removal carburetor cylinder head frontplate backplate obvious Caution fore disassembling engine lcok write down identifying features may indicate sides frontplate backplate go up sides cylinder head piston connecting rod go front engine no such features exist mark parts future reference reassembling engine may discover parts have nonsymmetrical features no obvious di rection indicated Gaskets should replaced gasket must reused should care fully removed before submerging parts cleaning solution Note side gasket faces parts screws different lengths note screws go AbouttheAuthor Walt Wilson started build ing solid model airplanes before WW II interest evolved through Control Line Radio Control several years raced tether cars winning scores tro phies held tether car world speed record 15177mph year mid-i 950s Since has very successful racing quarter midget cars stock cars several types stock-bodied drag race cars Along way set several track American Hot Rod Association world records wife Suzi currently very active sports car rallying Wilson has flying RO 15 years Pylon Racing Scale major areas interest has done virtually own engine preparation forms racing through years technical illustrator advanced manage ment currently publications super visor major electronics manufacturer St Louis Some engines have integral frontplates some cases piston connect ing rod cant removed removing cylinder liner engines sufficient clearance just slip off connecting rod crank pin just trying clean up engine after crash journey dirt may able wash wipe away enough foreign matter complete disas sembly However assured thor ough cleanup overhaul faithful power plant must remove piston connecting rod Most ABC Aluminum piston Brass sleeve hard Chrome plating cylinder liners dont fit crankcase very tightly can removed simply removing frontplate crankshaft possible pushing piston toward top bore Keep gently pushing sleeve will usually come out its stubborn piston doesnt fit tight enough Popsicle stick can inserted exhaust port pushed upward piston get sleeve started out put metal objects exhaust port Use wcod dont use much force piston connecting rod could damaged carbon varnish deposits exist around outside exhaust port sleeve may have removed before sleeve will slip out heavy-duty cleaning like luse automotive carbure tor cleaner auto parts store Use according directions can dont get hands Caution Engine parts made plastic will usually destroyed tf exposed solvent cleaner will remove burned congealed oil carbon varnish paint layers skin other non-metallic materials dipped cleaner will also pit discolor metal parts left too long also smells bad use wellventilated area Flush lots running water sleeve still wont come out Gator RC Products sells set pullers removing stubborn sleeves bearings good investment going very much engine work consist April 1986 41 correctly reassemble engine very Tools such heavy-duty puller homemade wire hook useful engine disas important note non-symmetrical features sembly Use care mar scratch parts stubborn remove disassembiing good example isthe small offset oil hole inthisconrod heat used help remove tight sleeve boiling water torch sleeve crankcase should both placed tops until cool avoid possible warpage split brass ring between tapered flat washer expands nut tightened threaded rod brass ring placed inside top sleeve nut tightened grip sleeve weighted slide hammer rod used knock out sleeve Unfortu nately last report Gator RC sleeve bearing pullers available larger engines pullers come two sizes 60-size sleeves smaller 60-size rear crankshaft bearings bearing puller may also fit some smaller engine sleeves Iron steel sleeves usually fit crank case tighter ABC sleeves almost always harder remove above-mentioned pullers arent available sleeve wont come out normal amount pulling pushing crankcase may heated boiling water aluminum crankcase will expand iron sleeve hopefully make easier remove crankcase should placed upside down top cylinder pan water being heated avoid warpage lay its side Its usually hot enough water comes boil Use oven mitt handle piece 062 music wire can bent hook grasp port sleeve pulling out Dont use hook unless plan replace sleeve may damage cylinder bore top port sleeve removed set crank case sleeve tops cool Caution Dont rest heated sleeve its side intend reuse Bearings crankshaft should checked play binding replace necessary Sometimes thorough cleaning bearings will correct binding caused dirt metal chips bearings can checked rotating crankshaft piston connecting rod removed feeling binding shaft should turn smoothly Usually bearings good free dirt chips after engine cleaned crankshaft oounterweight can turned approximately 900 bottom released will settle bottom position itself Heavy congealed oil frontplate bearings may prevent bearings good Dont assume bearings bad crankshaft wont settle itself good quality ball bearings kept clean theyll usually outlast rest engine cant feel catching binding bearings probably good Some engines designed rear crankshaft bearing supported frontplate fits bore crankcase checking bearings type engine piston connecting rod should removed frontplate reassembled crankcase bearings properly supported 42 Model Aviation Some engines such Supertigre X-60 have pin assure sleeve prop erly oriented aligned crankcase Other engine manufacturers K&B shown ThissleevefortheK&B65ccenglneshows sometimes use notches sleeve relative positions portsshouldyou flange alignment head screws forget reassembling exhaust port right will located higher sleeve intake ports centerand left 1-ln-dia hole 2 x4 makes handy holding fixture several rebuilding length wood dowel used drive operations performed 40-size front bearing out frontplate Wood frontpiate assembly Engines engine nevera metal punch should always used parts will ruined clamping vise avoid damage engine parts wood block used protect crank shaft seating rear bearing re seating will necessary after crash replacing bearings eltherthe crank pin connecting rod rub backplate 1 SCREW 2 GLOW PLUG 3 WASHER 4 HEAD 5 PISTON RING 6 PISTON 7 WRISTPIN 8 CONNECTING ROD 9 SLEEVE 10 CRANKCASE 11 EXHAUST ROTOR 12 BACKPLATE 13 EXHAUST ROTOR LEVER 14 LINK & SPRING 15 LOCKWASHER 16 SCREW 17 CARBURETOR 18O RING 19 CRANKSHAFT 20 REAR BALL BEARING 21 FRONTPLATE 22 FRONT BALL BEARING 23 PROP DRIVE HUB 24 PIN 25 SETSCREW 26 PROP ADAPTER STUD 27 PROP WASHER 28 PROP NUT 29 SETSCREW K&B 40 RC #8011 IllUSTRATION BY WALT & SUZI WILSON dont free up dunk dishwashing water few minutes slosh around try again Some people may agree procedure works bearings free feel smooth dry assembly paper towels blow out water much can oil crankshaft bearings liber ally Marvel Oil favorite light machine oil dont get out water oil steel parts well will rust Alcohol may used washing instead detergent/water detergent much less expensive least effective find impossible get bearings turn freely cleaning proceed follows Remove prop drive hub engines will fall off some cases may stubborn Try holding hub fingers tapping end crankshaft plastic hammer dont have plastic hammer regular hammer may used block wood softer metal such aluminum brass protect end crankshaft Caution Dont hit end crankshaft steel hammer may ruin threads Some engines such older K&B 40 may have drive hub pinned place and/or held place setscrew sure pins setscrews etc removed Small pullers usually available automotive tools sold will get job done else fails older K&B 40 necessary use hammer drift punch crankshaft re cessed hub K&B recommends 2 1 3 6 1 10 K13 r- i1 207 V Iill j2122 29 21 28 25 can test feel shaft bearings bearings become worn excessive ly bore frontplate between bearings will also wear allow fuel blow out through front bearing leakage appears excessive frontplate should also replaced Most engines blow fuel out front bearing some extent little bit blowby no indication excessive wear fact some blowby necessary lubricate front bearing modern engines have ball bearings crankshaft Some older less expensive engines have bronze bushings support crankshaft engine bronze bushing crankshaft shows excessive wear frontplate should replaced worn-out bronze-bushed frontplate integral crankcase would consider abandoning overhaul ing project Replacement crankcase addition other required parts very likely exceed price new engine have old engine bronze bushing badly worn parts no longer available may want investi gate knurling Automotive machine shops knurl worn auto engine valve guides replaceable ream original size may able to crankshaft bushing old model engine brainstorming havent yet occasion try Its possible alternative though really de- assembled frontplate returned terinined restore old engine factory service required cleaning replacing ball bearings hub removed try push out crankshaft must remove the crankshaft through bearings Fre crankshaft bearings quently crankshaft will push right out bearings frontplate dam- though luck usually wont aging anything First try clean doesnt push out try holding frontplate assembled frontplate bearings well tapping end crankshaft as engine parts soaking hot described above Again dont hit end water liquid dishwashing detergent crankshaft directly steel hamAfter few minutes remove frontplate merl doesnt work try supporting assembly solution flush frontplatewithwoodblocks drill hole running lukewarm water Rotate crank- 2 x 4 hole saw slightly larger shaft spin keep flushing bearings crankshaft counterbalance supporting water until feel smooth Continued page 126 April 198643 11 1 N 12N DG DESIGNS Full Body Pilot KIt Lightest Pilot available oLIfelIke vinyl la tex rubber parts Easy assemble finish eBulid either barnstormer sportsman pilot eKit contains pilot head hands boots helmet cap goggles full templates easy instructions eFully positionable & moveable Some simple sewing required Weight Price 116 Scale 2oz* $ 795 1/4 Scale 4 oz $ 995 1/3Scale 6oz $1695 Weight may vary depending material used construction DGA DESIGNS Bust Pilot Kit Weight 1/6Scale 75oz 1/4 Scale 1Soz 1/3 Scale 225 oz Price 595 795 $1495 Lightest bust pilot available eLifelike vinyl latex rubber parts Easy assemble finish Build either barnstormer sportsman pilot Kit contains pilot head helmet cap goggles jacket instructions See dealer order direct Add $100 shipping direct orders Send $100 current catalog Dealers inquiries invited NYS Aesidents add 7 percent sales tax Send Check MO Allow 3 weeks check clearSorry-NO CODs Ei1wu ml Radio Technique/Myers Continued page 123 can perform same kinds tests enough interest exists will spend few columns simple test techniques want send note either MA s publisher George M Myers 70 Froehlich Farm Rd Hicksville NY 11801 Engines/Wilson Continued page 43 frontplate hole try hitting crankshaft little harder cases will job else fails automotive machine shops have press will definitely remove crankshaft Inspect crankshaft scoring grooves discoloration crankpin area around between bearings crankshaft shows roughness wear areas should re placed Again look replacement price before proceeding usually expensive part indication outer races bearings have turning frontplate frontplate should also replaced next challenge removing bearings frontplate front bearing inner race almost always smaller bore frontplate piece wood dowel approximate size bore frontplate can used hammer tap out front bearing rear bearing tight enough stay crankshaft puller used remove drive hub will get off have Gator RC bearing puller removal rear bearing frontplate should no problem Otherwise try heating frontplate pan boiling water Hopefully aluminum frontplate will expand steel bearing outer race allowing removed sufficient room previouslymentioned wire hook may inserted through bearing inner bore help pull out Again use cooking mitt handle frontplate during procedure Reassembly New bearings should gent ly tapped place frontplate plastic hammer Tap around outer race being careful bearing goes bore evenly Dont let bearing get cocked bore crankshaft can used guide get bearing straight sure bearing tapped way bore Keep clean dont want ruin new bearings bearings place oil insert crankshaft prop drive hub K&B 40 must aligned pin holes setscrew match cor responding hole flat crankshaft engines fits tight must driven place hammer Again protect hub counterbalance crankshaft wood blocks ham mering pin hole hub aligned pin hole crankshaft drive roll pin place tighten setscrew other engines drive hub simply slips place Rotate crank shaft few times assure turning freely havent picked up dirt bearings Ring-type pistons sleeves piston rings available separately need purchased matched sets fit piston ring-type engine critical other types unless special racing engine being assembled Some engines have small pin ring groove hold ring given position respect ports carefully check such pin before installing ring piston Some rings such Dykes ring K&B 40 have top bottom cases direction obvious doubt look original piston ring Insert ring cylinder sleeve push little way piston square bore should gap about 0002 inch bore between ends ring no feeler gauge available check see light visible between ends clear ance probably okay engines bore i less no gap visible remove ring file sand ends slightly holding ends together rubbing thin file wet-or-dry sandpaper between File little check often its easy go too far ruin ring ring gap correct clean up ring sure no burrs around ends Carefully spread ring slip over top piston ring groove Align ends pin has Check fit big end connecting rod crankpin should bind does get another connecting rod its unlikely new connecting rod will fit properly Compare new connecting rod old de termine side goes front engine Frequently oil hole side big end fits crankshaft should face specific direction Pistons baffle fence top should have baffle toward intake ports Being sure parts clean facing proper direction oil assemble connecting rod piston inserting wrist pin Most wrist pins have pads ends made Teflon some other relatively soft material pre vent scuffing sleeve Make sure pads place Some wrist pins go way through piston have such pad instance pad obviously end will exposed sleeve area piston pin exposed should aligned ports sleeve Pistons/sleeves ABC engines 126 Model Aviation monthly publication covering International RC Soaring Scene $1 6/yr US Canada & Mexico $24/yr elsewhere via airmail Post Office Box 269 Peterborough NH 03458 justto get Spar 57 Area SOOsqot Weiglst 64 00 loadiug lOooInqft Eagine Requned 4 nyolo 40 2 cycle 2535 Rodio 4 channel loss instructions youll ever buy coos tell put oil money fantartic kit uut u fautastic bou comes hr Want kooro muse ahoot 440 other plaue aud electrouic hits Seud $200 116W 1911s55 PO Hou5L1EJ Hi8gicsoille 540 64077 call us 016 584-7121 order 44 1 00 lrorrdhssg ec Coming 460 NEW lapped iron pistons/sleeves available matched sets no fitting re quired ABC pistons designed fit sleeve tightly top stroke dont alarmed condition discovered heat running en gine expands sleeve piston proper clearance automatic Some ABC engines also use piston rings cases frontplate integral crankcase sleeve removed before piston connecting rod could removed will necessary reassemble piston connecting rod onto crankpin before sleeve inserted Slip piston sleeve bottom sleeve inserted crankcase sounds com plicated reasonable care its difficult engine piston rings must assembled way sleeve usually has tapered bore bottom assist compressing rings Some engines have clearance holes flange top sleeve head screws Some have alignment pin crankcase matches notch flange top sleeve Others have no alignment devices no alignment feature present obvious orienta tion sleeve crankcase may determined follows two-cycle model engine have encountered exhaust ports physi cally located nearer top sleeve intake ports Locate exhaust ports face toward exhaust port crankcase push sleeve place aligning ports crankcase ports go parts clean sleeve will almost always slip place no ringer pressure hangs up way make sure ports lined up place crankcase sleeve upside down clean surface such table push place firmly palm hand bottom crankcase event sleeve will push crankcase reasonable pres sure place sleeve freezer hour may cause sleeve contract enough go crankcase Check time assure ports sleeve aligned ports crankcase over ABC piston rod assembly must sleeve time sleeve assembled crankcase will impossible usually insert ABC piston through top sleeve due tight fit Insert bottom Iron pistons ring-type pistons may assembled sleeve after sleeve crankcase except course frontplate integral crankcase Oil piston wrist pin sleeve generously before assembly ABC iron pis tons simply oriented pushed sleeve proper direction Pistons rings require little effort aligning pin ring groove piston align ring gap pin no pin present ring gap should oriented line ports Push ring groove fingernails gently push piston sleeve may necessary maintain gentle pressure top piston holding ring against top sleeve finger pushing ring groove piston other fingernails its right piston will slip sleeve Align piston bore lower end connecting rod perpendicular centerline crankshaft gasket used place frontplate proper position gasket being reused put exactly same position facing same way removed No sealers necessary Oil crankpin align con necting rod slip frontplate place front crankcase backplate removed support connecting rod finger frontplate crankpin inserted dont go easily find outwhats wrong Dont force everything aproperly aligned will easily slip place Turn crankshaft few times assure everything moves smoothly Insert four frontplate screws snug Tighten little time going first screw directly opposite working around frontplate until tight Dont twist off strip threads crankcase isealuminum threads delicate Check once assure sleeve still aligned ports crankcase install cylinder head Most modern engines dont use head gas kets some use thin shims under head shim engine disassembled sure replaced reassembling Snug screws first tighten little time again going first screw directly opposite working around head Some engines use squish band head some cases specific clearance designated instructions come engine clearance can checked using product called Plastigage available various clearance ranges auto parts stores soft plastic material looks like wire small piece placed top piston will contact squish band flat outer diameter portion head protrudes cylinder before head installed Install head rotate crankshaft couple times remove head Check width mashed Plastigage scale came Dont worry about clearances connecting rod wrist pin allowing piston come closer two-cycle engine running compression combus Continued page 130 April 1986 127 W o hear lot about ocr 440 kit Wish its unique miug desigs 40 four sleoket flyr slum smooth shut just crcs beheor mken see outside loop whot menu Oke half thror / lIe Thurs euchoutmeur Ibis plane after fem ucrubatic maneurets uetves atent frayrd nuds llkr youoe just test flown full wale homehuilt.you feel I.C IOhe yuuoe floated through Now A/ n e iiiS dM/itliVthurs wltos Suuday/llport flying about . LAS 1 e four strokers quiet hut powerful traits ordy odd thdll Joy Ride 4 40 moro thiog eorr built ACE plane kit already know gearifyingit con prIde oucreloes designing moss complote kits offort SAILPLANE LAUNCH EQUIPMENT FOR EVERY S PORT WINCH source QUIET FLIGHT supplies hi-starts accessories electric motors & reducers batteries chutes braided nylon line tow line drums more. VISA MASTERCARD DAVEY 1Pm lE CoRPoRATmN ONE WOOD LANEMALVERNPA19355 215644-6772 SEND SASE FOR INFO Engines/Wilson Continued page 127 tion maintain constant down pressure piston Plastigage mashed out too wide clearance too close thicker shim combination shims shouldbe used Plastigage mashed out wide enough clearance too great thinner shim no shim should used clear ance correct clean off Plastigage piston head reassemble head engine gasket used backplate put place mount backplate engine Tighten screws previously described Rotate crankshaft sure crankpin and/or connecting rod rubbing backplate binding detected tighten propeller crankshaft hold ward doesnt cure problem remove frontplate Using wood block protect crankshaft tap back crankshaft center hammer sure crankshaft rear bearing fully seated forwardmost position Reassemble engine try again crankshaft bearings fully seated should no contact backplate fully-assembled engine turns feels free except case new ABC engine may bind top stroke screw fresh glow plug reassemble carburetor engine 0-ring hold down carburetor against 0-ring tight ening screws nut hold place overhauling procedures have finished engine can broken using same procedures new information article applies generally two-cycle front-intake RC engines conventional constructions Other types engines require somewhat different procedures have better way tasks please write let know Walt Wilson 3000 Persimmon Dr St Charles MO 63301 Addresses companies products mentioned GatorRC Products 3713 Pompano Dr Pensacola FL 32504 K&B Manufacturing 12152 Woodruff Ave Downey CA 90241 Marvel Oil Company Inc Port Ches ter NY 10573 Sealed Power Corp Plastigage 100 Terrace Plaza Muskegon MI 49443 RC Soaring/Pruss Continued page 49 next two years may also thank outgoing officers served two terms four years Warren Plohr LSF/334 Presi dent Larry Jolly LSF/3579 Vice-Presi dent Ken Bates LSF/604 Secretary Cal Sobczynski LSF/2487 Treasurer During 1985 seven gents names added Level V list bringing total up 46 Earle Latimer LSF/31 19 Lansing MI Terry Edmonds LSF/463 Iowa City IA Dale Harber LSF/1880 Yoder IN Charron Smith LSF/4093 Grand MI Richard Ransom LSF/4747 lonia MI Thomas Dickey LSF/3816 Gaithersburg MD Robert Schow LSF/166 Vienna VA Congratulations As column closing out word received Larry Jolly representing USA won first place South Africa flying first International F3H Cross-Country event ever held Larry flying original design Comet Details later article Larry himself Until next month good lift Dan Pruss 131 E Pennington Ln Plainfield IL 60544 RC Electrics/Kopski Continued page 51 lengths nichrome Because nichrome has relatively stable resistance temperature variation copper other conductive wire could used task temperature coefficient copper -many metals around plus % minus 5o per 100 C Thus value shunresistance would vary quite noticeably ambient internal temperature thereby rendering such metals useless purposes later wire used readily available modelers foam-cutting wire RC Modeler PO Box 487 Sierra Madre CA 91024 Cost $225 five-foot length postpaid As received wire measured little over three ohms sug gest confirm yours just sure information given di rectly applicable Ill try give sufficient detail just case can ac commodate somewhat different resist ances few words now before get how-to nittygritty Youll recall discussion last month about ohmmeter function multimeter measure resistance five-foot length nichrome wire set meter selector switch lowest resistance range short test leads together carefully zero ohms adjustment knob until meter pointer rests 0 ohms scale Its often good practice tape meter face gently fingertip sure needle has reached its true resting position connect test leads end nichrome wire Make sure leads make tight contactboth zeroing operation connection What should get 3 33 ohms 130 Model Aviation POW OM RETRIEVER HOBBY HAMMER $Q~ APPROXLENGTH7/Extra Tip INCLUDES$125 ONE STEEL AND ONE BRASS TIP Send check Money Order M &WMODELS PO Box 6627 Huntington Beach CA 92615 Add 150 Post & Hand Rae add 6% tax