Don Jehilk LfLJLLI PREPARING New Engines Running exception Cox engines smaller 15 displacement standard prac tice disassemble inspect prepare new engine before run dont follow practice advise begin benefits will described succeeding articles will need several tools basic job preparing engine en gines today supplied wrenches used disassembly am glad see finally happen use properly fitted screwdrivers wrenches really important past modelers bought assortment drivers wrenches often didnt fit properly Dont buy proper fitting toolsits good idea take engine select good qual ity tools fit screws en gine small crescent wrench will fit variety prop nut sizes good glow plug wrench will take care external screws nuts plug RC carburetors ten require additional screwdrivers wrenches Miscellaneous tools include tweezers needle-nose pliers X-acto knife jewelers files addition tools will need following items solvent solutionI have found 50-50 mixture odorless paint thinner lacquer thinner does best job can find both Sears Wards hardware paint stores 2 wet dry sandpaper 320 600 grits 3 old toothbrush 4 duPont White Auto motive Rubbing Compound 5 3-in-I oil will mention special tools mate rials following procedures may used serious competitor go extra step engine preparation Disassembly Read instructions sup plied engine Prepare clean work area put piece white sheet bench work under strong light use standard pro cedure disassembling engine First remove glow plug turn engine over slowly feel internal drag occurs note occurs terms piston position cylinder Next re New piston lapped pistonnote matte finish lapped piston move rear cover turn engine again noting drag put prop shaft tighten normally turn again see ball bearings proper ly mounted Remove cylinder head loosening opposite screws fraction first round unscrew way head removed turn again drag usual procedure remove cyl inder sleeve remove piston/rod assembly backing rod off crankpin instructions engine may specify different method Removal wristpin piston through ex haust port removal frontplate bolted point remember force piston/rod assembly order remove engine bent rod damaged rod bearing hole can re sult Before final disassembly rotate shaft again signs drag Seems tedious weve just started Cleaning Thoroughly clean engine parts 50-50 cleaner old tooth brush should reach corners cracks Ball bearings deserve special care engine has ball bearings try soaking housing removing bearings object remove dried oil residue portion bearings engines have worn flats balls cause balls could rotate freely races cant completely free bearings remove housing cleaning Heat housing oven 3250 F should expand housing allow bearings drop free Continued page 99 Lapping piston cylinder compound WI Checking shaft/bearing assembly prop tricks its now everyday fact model flying constant jeopardy some parts country because noise complaints Flying sites getting harder get harder hold onto clubs nov require mufflers fields Watch heads turn frowns appear start up unmuffled engine presence mbdelers have using mufflers some time Its just matter time before mufflers required everywhere best can expect far-sighted enough police problem voluntarily now before its too late dont model fly ing know could easily banned areas unsympathetic judges juries court action chief responsibility Contest Board write equitable rules governing model competition Basically think would unfair scale competitor club mufflers required able compete against modeler area noise problem mufflers required would competing basis facing same obstacles cases handled properly silencer can effectively used increase realistic impression performance scale model silencer can used route hot exhaust gases often cause overheating out engine compart ment scale-like manner Throttle equipped engines usually always idle smoother dependably muffler because back pressure creates Several commercially available exhaust manifolds market can completely concealed inside cowlings wont fit inside models cowl can usually fabri cate custom-shaped manifold sheet metal FAT Scale rules give special inge nuity points effective handling muffler installation Maybe AMA rules should too Only very few cases does addi tion silencer have detract appearance scale model cases AMA rules prohibit judge subtract ing scale points account Some people have argued what about psychological effect exposed muffler judge during static judging Im going worry about psychological effect something judge has instructed disregard Id con cerned about effect models flight would have overworked maybe irritable judge has previously watching other scale models fly pleasing realistic sounding muffled engines Note CL Stunt impressions also very important almost competitors Nats voluntarily use muffler vast majority CL AMA Scale fliers compete Nationals already using silencers order comply FAT rule improve flight realism KB aron inYou HB Engines have now well acc~ public available ever dealers too may now enjoy RC boating car racing HE Engines precision power performance reliability HB Engine includes Perry carburetor several models offer PDP Perry Directional Porting increased power speed up 1500 RPMs Sizes available 12 15 20 25 40 50 61 displacement Let HE precision maneuverability speed satisfy Baron complete catalog see local dealer write NB ENGINES Bavarian Precision Products Co formerly Helmut Bernhardt Precision Movements Co PO Box 6 New Canaan Ct 06840 203 966-8781 parts available stock pt service assured Dealership inquiries invited impression model Ii have keeping up forma tion encompassing FF CL & RC national scale association prob ably heard indeed founded Riverside Nats meeting about 75 scalers elected temporary board officers will try get organiza tion off ground According Bob Underwood President-elect chief whip-cracker plan now set up dues structure register members start ing around first year first newsletter will also sent out about time should have definite infor mation next month Mike Gretz Box 162 Montezuma Iowa 50171 Engine Technique/Jehlik continued page 48 dont come free use wood dowel gent ly force hot housing complete cleaning process until bearing spins freely Remember metic ulous clean part perfectly Inspection Preparation Reassemble engine follows oil parts residue odorless paint thinner light oil will protect parts during following checks 1 Reinstall crankshaft front hous ing tighten prop turn carefully shaft does turn perfectly free several possible problems a Shaft housing too tight has flaw bore usually dent bump surface handling during manu facture Heres use duPont white rubbing compound Remove ball bearings put light coating compound shaft insert housing turn hand electric drill drill press Thoroughly clean exam ine housing see compound has polished high spot spot evident continue compound until housing bore has uniformly matte finish b Ball bearings may properly seated resulting improper dimensional relationship between bearings crank shaft First test tighten spin prop may find shaft doesnt rotate freely Grasp prop push pull shaft bearings properly installed should feel small amount back forth play approximately 003 dont get heat housing sure 1 rear bearing outer race fully forward housing 2 shaft rear bearing pushed ward slide front bearing shaft rearmost position heated housing should trick Spin prop hous ins till hot after has cooled January1978 99 sure spins freely both ways c Could bad bearing usually noted because clicks rotated sure bearing clean before deciding re place Connecting Rod basic check make sure hole bottom end chamfered both ends Sometimes rods will rub forward against crankshaft bushing hole rod will inter fere small radius ground between crankpin crankdisc chamfer should establish clearance inter section Piston/Sleeve three basic types lapped lapped ABC ringed piston treated differently although basic goal same round sleeve bore little no taper above exhaust port matched round piston ring has adequate clearance before run ning have observed engines run tight new place stress connect ing rods bearings wristpin/piston fits etc results reduced maximum per formance broken dont mean cant run engine prior fitting provided undue stress placed operating parts during process procedure ensures stress-free break-in Lapped Piston Regardless whether clean piston will pass freely through sleeve use duPont rubbing compound Smear light coating piston sleeve lap piston using connect ing rod move piston sleeve piston laps smoothly drag throughout bore clean thoroughly examine sleeve care fully under bright light shiny spots usually occur around port areas sometimes below ports sleeve has warped Continue lapping cleaning examining until sleeve has uni formly matte-finished bore clean parts very carefully solvent tooth brush until can wipe surface white cotton sheet come clean same above believe proper pis ton/sleeve clearance essential before running experience indicates too-tight fit will result harder piston pushing brass sleeve deforming necessary achieve running fit have unable extract maximum perform ance happens Its difficult de termine exact clearance required prior running lap free run engine carefully briefly Remove head carefully examine chrome surface sleeve observe extra shiny areas especially top stroke fit still tight Extra lapping special proce dures such honing machine lapping can used correct problem Ringed Piston piston ring utmost importance must absolutely round have small gap possible remain round installed piston conditions exception rather rule basic problem establish perfectly round paralleled bore sleeve Since dont have piston lap can take chance having true sleeve make lap cant machine shop can machine bar brass aluminum bare slip fit sleeve Given true sleeve smear light coat compound sleeve place rings between two piston skirts similar tight fitting cylinders lap rings sleeve Lap little first clean examine ring rubbing surface polish Lap until truly important small ring gap round ring will develop power regardless gap size final test push ring sleeve squarely hold up product review product review product review Wing Cutout Tool better mousetrap cate gory Groovers provide effective answer nuisance problem cutting out foam ser vos landing gear retract wells ailerons torque tubes etc Preformed wire cutters fit gun-type soldering irons Die-cut templates includedl make such chores snap Anon Enterprises also offers over 60 different foam wing cores almost popular RC ma chine can think including flying lawnmower molded wheels Firm has over 500 plans templates will quote plan Also has Doods nylon mounting bolt sets speed wrench threaded wood block Anion Enterprises PO Box 337 Hwy 56 West Edgerton KS 66021 Lapped ABC procedure essentially product review product review product review light look signs light between ring sleeve No light round ring Install ring piston carefully Cylinder Sleeve Ive always put dab compound under lip sleeve rotated crankcase sure lower surface sleeve lip matched mating surface top case Cylinder Head Same above dab compound mate both surfaces regard less gasket may supplied engine careful lap head bore surface sleeve tight fit tween head sleeve essential Back Cover Lap back cover rear mating surface case Cleaning Assembly Recheck parts sure absolutely clean Oil lightly 3-in-l oil assemble engine Tighten opposite screws little time turn crankshaft after part installed sure finally put glow plug flip prop will know difference engine will loose compression seal will surprise Final Examination Wipe external sur faces clean look signs oil leaking past sealing surfaces everything okay store engine plastic bag until ready run test stand Conclusion Development basic skills preparing engine run essen tial discussion intended get modelers started dont already pre pare engines will enjoy acquiring skills needed understand seemingly small details have substantial effect engine performance Next month well run engine test stand Don Jehlik 438A Schweer Dr Star Route 1 Hawthorne NV 89415 Scale Model/Preston continued page 55 falls napalm types excepted expect score 10 points Another scale operation may think dead giveaway operation flaps have received both tens zeros flap demonstrations Monocoupe zero awarded judge claimed able see flaps move during flight after cycled down up four times during flight takeoff missed approach separate flap demo landing am now reluctant use flaps option still use landings since trim change nose up advantageous keeping model nosing over during landing though may elect use flaps lieu flying maneuver may 100 Model Aviation FAMOUS BRITISH DIESELS D/C PAW M/E rj * *NEW* * CATALOG-DIESEL HANDBOOK $150 pp HOBBY HIDEAWAY DELAVANILL61734 MORRISONSCALE DRAWINGS EPLA TECHCATALOG 25c ntefl10t 01W 40500 McKenzie Hwy vida Oregon 97450
Edition: Model Aviation - 1978/01
Page Numbers: 48, 99, 100
Don Jehilk LfLJLLI PREPARING New Engines Running exception Cox engines smaller 15 displacement standard prac tice disassemble inspect prepare new engine before run dont follow practice advise begin benefits will described succeeding articles will need several tools basic job preparing engine en gines today supplied wrenches used disassembly am glad see finally happen use properly fitted screwdrivers wrenches really important past modelers bought assortment drivers wrenches often didnt fit properly Dont buy proper fitting toolsits good idea take engine select good qual ity tools fit screws en gine small crescent wrench will fit variety prop nut sizes good glow plug wrench will take care external screws nuts plug RC carburetors ten require additional screwdrivers wrenches Miscellaneous tools include tweezers needle-nose pliers X-acto knife jewelers files addition tools will need following items solvent solutionI have found 50-50 mixture odorless paint thinner lacquer thinner does best job can find both Sears Wards hardware paint stores 2 wet dry sandpaper 320 600 grits 3 old toothbrush 4 duPont White Auto motive Rubbing Compound 5 3-in-I oil will mention special tools mate rials following procedures may used serious competitor go extra step engine preparation Disassembly Read instructions sup plied engine Prepare clean work area put piece white sheet bench work under strong light use standard pro cedure disassembling engine First remove glow plug turn engine over slowly feel internal drag occurs note occurs terms piston position cylinder Next re New piston lapped pistonnote matte finish lapped piston move rear cover turn engine again noting drag put prop shaft tighten normally turn again see ball bearings proper ly mounted Remove cylinder head loosening opposite screws fraction first round unscrew way head removed turn again drag usual procedure remove cyl inder sleeve remove piston/rod assembly backing rod off crankpin instructions engine may specify different method Removal wristpin piston through ex haust port removal frontplate bolted point remember force piston/rod assembly order remove engine bent rod damaged rod bearing hole can re sult Before final disassembly rotate shaft again signs drag Seems tedious weve just started Cleaning Thoroughly clean engine parts 50-50 cleaner old tooth brush should reach corners cracks Ball bearings deserve special care engine has ball bearings try soaking housing removing bearings object remove dried oil residue portion bearings engines have worn flats balls cause balls could rotate freely races cant completely free bearings remove housing cleaning Heat housing oven 3250 F should expand housing allow bearings drop free Continued page 99 Lapping piston cylinder compound WI Checking shaft/bearing assembly prop tricks its now everyday fact model flying constant jeopardy some parts country because noise complaints Flying sites getting harder get harder hold onto clubs nov require mufflers fields Watch heads turn frowns appear start up unmuffled engine presence mbdelers have using mufflers some time Its just matter time before mufflers required everywhere best can expect far-sighted enough police problem voluntarily now before its too late dont model fly ing know could easily banned areas unsympathetic judges juries court action chief responsibility Contest Board write equitable rules governing model competition Basically think would unfair scale competitor club mufflers required able compete against modeler area noise problem mufflers required would competing basis facing same obstacles cases handled properly silencer can effectively used increase realistic impression performance scale model silencer can used route hot exhaust gases often cause overheating out engine compart ment scale-like manner Throttle equipped engines usually always idle smoother dependably muffler because back pressure creates Several commercially available exhaust manifolds market can completely concealed inside cowlings wont fit inside models cowl can usually fabri cate custom-shaped manifold sheet metal FAT Scale rules give special inge nuity points effective handling muffler installation Maybe AMA rules should too Only very few cases does addi tion silencer have detract appearance scale model cases AMA rules prohibit judge subtract ing scale points account Some people have argued what about psychological effect exposed muffler judge during static judging Im going worry about psychological effect something judge has instructed disregard Id con cerned about effect models flight would have overworked maybe irritable judge has previously watching other scale models fly pleasing realistic sounding muffled engines Note CL Stunt impressions also very important almost competitors Nats voluntarily use muffler vast majority CL AMA Scale fliers compete Nationals already using silencers order comply FAT rule improve flight realism KB aron inYou HB Engines have now well acc~ public available ever dealers too may now enjoy RC boating car racing HE Engines precision power performance reliability HB Engine includes Perry carburetor several models offer PDP Perry Directional Porting increased power speed up 1500 RPMs Sizes available 12 15 20 25 40 50 61 displacement Let HE precision maneuverability speed satisfy Baron complete catalog see local dealer write NB ENGINES Bavarian Precision Products Co formerly Helmut Bernhardt Precision Movements Co PO Box 6 New Canaan Ct 06840 203 966-8781 parts available stock pt service assured Dealership inquiries invited impression model Ii have keeping up forma tion encompassing FF CL & RC national scale association prob ably heard indeed founded Riverside Nats meeting about 75 scalers elected temporary board officers will try get organiza tion off ground According Bob Underwood President-elect chief whip-cracker plan now set up dues structure register members start ing around first year first newsletter will also sent out about time should have definite infor mation next month Mike Gretz Box 162 Montezuma Iowa 50171 Engine Technique/Jehlik continued page 48 dont come free use wood dowel gent ly force hot housing complete cleaning process until bearing spins freely Remember metic ulous clean part perfectly Inspection Preparation Reassemble engine follows oil parts residue odorless paint thinner light oil will protect parts during following checks 1 Reinstall crankshaft front hous ing tighten prop turn carefully shaft does turn perfectly free several possible problems a Shaft housing too tight has flaw bore usually dent bump surface handling during manu facture Heres use duPont white rubbing compound Remove ball bearings put light coating compound shaft insert housing turn hand electric drill drill press Thoroughly clean exam ine housing see compound has polished high spot spot evident continue compound until housing bore has uniformly matte finish b Ball bearings may properly seated resulting improper dimensional relationship between bearings crank shaft First test tighten spin prop may find shaft doesnt rotate freely Grasp prop push pull shaft bearings properly installed should feel small amount back forth play approximately 003 dont get heat housing sure 1 rear bearing outer race fully forward housing 2 shaft rear bearing pushed ward slide front bearing shaft rearmost position heated housing should trick Spin prop hous ins till hot after has cooled January1978 99 sure spins freely both ways c Could bad bearing usually noted because clicks rotated sure bearing clean before deciding re place Connecting Rod basic check make sure hole bottom end chamfered both ends Sometimes rods will rub forward against crankshaft bushing hole rod will inter fere small radius ground between crankpin crankdisc chamfer should establish clearance inter section Piston/Sleeve three basic types lapped lapped ABC ringed piston treated differently although basic goal same round sleeve bore little no taper above exhaust port matched round piston ring has adequate clearance before run ning have observed engines run tight new place stress connect ing rods bearings wristpin/piston fits etc results reduced maximum per formance broken dont mean cant run engine prior fitting provided undue stress placed operating parts during process procedure ensures stress-free break-in Lapped Piston Regardless whether clean piston will pass freely through sleeve use duPont rubbing compound Smear light coating piston sleeve lap piston using connect ing rod move piston sleeve piston laps smoothly drag throughout bore clean thoroughly examine sleeve care fully under bright light shiny spots usually occur around port areas sometimes below ports sleeve has warped Continue lapping cleaning examining until sleeve has uni formly matte-finished bore clean parts very carefully solvent tooth brush until can wipe surface white cotton sheet come clean same above believe proper pis ton/sleeve clearance essential before running experience indicates too-tight fit will result harder piston pushing brass sleeve deforming necessary achieve running fit have unable extract maximum perform ance happens Its difficult de termine exact clearance required prior running lap free run engine carefully briefly Remove head carefully examine chrome surface sleeve observe extra shiny areas especially top stroke fit still tight Extra lapping special proce dures such honing machine lapping can used correct problem Ringed Piston piston ring utmost importance must absolutely round have small gap possible remain round installed piston conditions exception rather rule basic problem establish perfectly round paralleled bore sleeve Since dont have piston lap can take chance having true sleeve make lap cant machine shop can machine bar brass aluminum bare slip fit sleeve Given true sleeve smear light coat compound sleeve place rings between two piston skirts similar tight fitting cylinders lap rings sleeve Lap little first clean examine ring rubbing surface polish Lap until truly important small ring gap round ring will develop power regardless gap size final test push ring sleeve squarely hold up product review product review product review Wing Cutout Tool better mousetrap cate gory Groovers provide effective answer nuisance problem cutting out foam ser vos landing gear retract wells ailerons torque tubes etc Preformed wire cutters fit gun-type soldering irons Die-cut templates includedl make such chores snap Anon Enterprises also offers over 60 different foam wing cores almost popular RC ma chine can think including flying lawnmower molded wheels Firm has over 500 plans templates will quote plan Also has Doods nylon mounting bolt sets speed wrench threaded wood block Anion Enterprises PO Box 337 Hwy 56 West Edgerton KS 66021 Lapped ABC procedure essentially product review product review product review light look signs light between ring sleeve No light round ring Install ring piston carefully Cylinder Sleeve Ive always put dab compound under lip sleeve rotated crankcase sure lower surface sleeve lip matched mating surface top case Cylinder Head Same above dab compound mate both surfaces regard less gasket may supplied engine careful lap head bore surface sleeve tight fit tween head sleeve essential Back Cover Lap back cover rear mating surface case Cleaning Assembly Recheck parts sure absolutely clean Oil lightly 3-in-l oil assemble engine Tighten opposite screws little time turn crankshaft after part installed sure finally put glow plug flip prop will know difference engine will loose compression seal will surprise Final Examination Wipe external sur faces clean look signs oil leaking past sealing surfaces everything okay store engine plastic bag until ready run test stand Conclusion Development basic skills preparing engine run essen tial discussion intended get modelers started dont already pre pare engines will enjoy acquiring skills needed understand seemingly small details have substantial effect engine performance Next month well run engine test stand Don Jehlik 438A Schweer Dr Star Route 1 Hawthorne NV 89415 Scale Model/Preston continued page 55 falls napalm types excepted expect score 10 points Another scale operation may think dead giveaway operation flaps have received both tens zeros flap demonstrations Monocoupe zero awarded judge claimed able see flaps move during flight after cycled down up four times during flight takeoff missed approach separate flap demo landing am now reluctant use flaps option still use landings since trim change nose up advantageous keeping model nosing over during landing though may elect use flaps lieu flying maneuver may 100 Model Aviation FAMOUS BRITISH DIESELS D/C PAW M/E rj * *NEW* * CATALOG-DIESEL HANDBOOK $150 pp HOBBY HIDEAWAY DELAVANILL61734 MORRISONSCALE DRAWINGS EPLA TECHCATALOG 25c ntefl10t 01W 40500 McKenzie Hwy vida Oregon 97450
Edition: Model Aviation - 1978/01
Page Numbers: 48, 99, 100
Don Jehilk LfLJLLI PREPARING New Engines Running exception Cox engines smaller 15 displacement standard prac tice disassemble inspect prepare new engine before run dont follow practice advise begin benefits will described succeeding articles will need several tools basic job preparing engine en gines today supplied wrenches used disassembly am glad see finally happen use properly fitted screwdrivers wrenches really important past modelers bought assortment drivers wrenches often didnt fit properly Dont buy proper fitting toolsits good idea take engine select good qual ity tools fit screws en gine small crescent wrench will fit variety prop nut sizes good glow plug wrench will take care external screws nuts plug RC carburetors ten require additional screwdrivers wrenches Miscellaneous tools include tweezers needle-nose pliers X-acto knife jewelers files addition tools will need following items solvent solutionI have found 50-50 mixture odorless paint thinner lacquer thinner does best job can find both Sears Wards hardware paint stores 2 wet dry sandpaper 320 600 grits 3 old toothbrush 4 duPont White Auto motive Rubbing Compound 5 3-in-I oil will mention special tools mate rials following procedures may used serious competitor go extra step engine preparation Disassembly Read instructions sup plied engine Prepare clean work area put piece white sheet bench work under strong light use standard pro cedure disassembling engine First remove glow plug turn engine over slowly feel internal drag occurs note occurs terms piston position cylinder Next re New piston lapped pistonnote matte finish lapped piston move rear cover turn engine again noting drag put prop shaft tighten normally turn again see ball bearings proper ly mounted Remove cylinder head loosening opposite screws fraction first round unscrew way head removed turn again drag usual procedure remove cyl inder sleeve remove piston/rod assembly backing rod off crankpin instructions engine may specify different method Removal wristpin piston through ex haust port removal frontplate bolted point remember force piston/rod assembly order remove engine bent rod damaged rod bearing hole can re sult Before final disassembly rotate shaft again signs drag Seems tedious weve just started Cleaning Thoroughly clean engine parts 50-50 cleaner old tooth brush should reach corners cracks Ball bearings deserve special care engine has ball bearings try soaking housing removing bearings object remove dried oil residue portion bearings engines have worn flats balls cause balls could rotate freely races cant completely free bearings remove housing cleaning Heat housing oven 3250 F should expand housing allow bearings drop free Continued page 99 Lapping piston cylinder compound WI Checking shaft/bearing assembly prop tricks its now everyday fact model flying constant jeopardy some parts country because noise complaints Flying sites getting harder get harder hold onto clubs nov require mufflers fields Watch heads turn frowns appear start up unmuffled engine presence mbdelers have using mufflers some time Its just matter time before mufflers required everywhere best can expect far-sighted enough police problem voluntarily now before its too late dont model fly ing know could easily banned areas unsympathetic judges juries court action chief responsibility Contest Board write equitable rules governing model competition Basically think would unfair scale competitor club mufflers required able compete against modeler area noise problem mufflers required would competing basis facing same obstacles cases handled properly silencer can effectively used increase realistic impression performance scale model silencer can used route hot exhaust gases often cause overheating out engine compart ment scale-like manner Throttle equipped engines usually always idle smoother dependably muffler because back pressure creates Several commercially available exhaust manifolds market can completely concealed inside cowlings wont fit inside models cowl can usually fabri cate custom-shaped manifold sheet metal FAT Scale rules give special inge nuity points effective handling muffler installation Maybe AMA rules should too Only very few cases does addi tion silencer have detract appearance scale model cases AMA rules prohibit judge subtract ing scale points account Some people have argued what about psychological effect exposed muffler judge during static judging Im going worry about psychological effect something judge has instructed disregard Id con cerned about effect models flight would have overworked maybe irritable judge has previously watching other scale models fly pleasing realistic sounding muffled engines Note CL Stunt impressions also very important almost competitors Nats voluntarily use muffler vast majority CL AMA Scale fliers compete Nationals already using silencers order comply FAT rule improve flight realism KB aron inYou HB Engines have now well acc~ public available ever dealers too may now enjoy RC boating car racing HE Engines precision power performance reliability HB Engine includes Perry carburetor several models offer PDP Perry Directional Porting increased power speed up 1500 RPMs Sizes available 12 15 20 25 40 50 61 displacement Let HE precision maneuverability speed satisfy Baron complete catalog see local dealer write NB ENGINES Bavarian Precision Products Co formerly Helmut Bernhardt Precision Movements Co PO Box 6 New Canaan Ct 06840 203 966-8781 parts available stock pt service assured Dealership inquiries invited impression model Ii have keeping up forma tion encompassing FF CL & RC national scale association prob ably heard indeed founded Riverside Nats meeting about 75 scalers elected temporary board officers will try get organiza tion off ground According Bob Underwood President-elect chief whip-cracker plan now set up dues structure register members start ing around first year first newsletter will also sent out about time should have definite infor mation next month Mike Gretz Box 162 Montezuma Iowa 50171 Engine Technique/Jehlik continued page 48 dont come free use wood dowel gent ly force hot housing complete cleaning process until bearing spins freely Remember metic ulous clean part perfectly Inspection Preparation Reassemble engine follows oil parts residue odorless paint thinner light oil will protect parts during following checks 1 Reinstall crankshaft front hous ing tighten prop turn carefully shaft does turn perfectly free several possible problems a Shaft housing too tight has flaw bore usually dent bump surface handling during manu facture Heres use duPont white rubbing compound Remove ball bearings put light coating compound shaft insert housing turn hand electric drill drill press Thoroughly clean exam ine housing see compound has polished high spot spot evident continue compound until housing bore has uniformly matte finish b Ball bearings may properly seated resulting improper dimensional relationship between bearings crank shaft First test tighten spin prop may find shaft doesnt rotate freely Grasp prop push pull shaft bearings properly installed should feel small amount back forth play approximately 003 dont get heat housing sure 1 rear bearing outer race fully forward housing 2 shaft rear bearing pushed ward slide front bearing shaft rearmost position heated housing should trick Spin prop hous ins till hot after has cooled January1978 99 sure spins freely both ways c Could bad bearing usually noted because clicks rotated sure bearing clean before deciding re place Connecting Rod basic check make sure hole bottom end chamfered both ends Sometimes rods will rub forward against crankshaft bushing hole rod will inter fere small radius ground between crankpin crankdisc chamfer should establish clearance inter section Piston/Sleeve three basic types lapped lapped ABC ringed piston treated differently although basic goal same round sleeve bore little no taper above exhaust port matched round piston ring has adequate clearance before run ning have observed engines run tight new place stress connect ing rods bearings wristpin/piston fits etc results reduced maximum per formance broken dont mean cant run engine prior fitting provided undue stress placed operating parts during process procedure ensures stress-free break-in Lapped Piston Regardless whether clean piston will pass freely through sleeve use duPont rubbing compound Smear light coating piston sleeve lap piston using connect ing rod move piston sleeve piston laps smoothly drag throughout bore clean thoroughly examine sleeve care fully under bright light shiny spots usually occur around port areas sometimes below ports sleeve has warped Continue lapping cleaning examining until sleeve has uni formly matte-finished bore clean parts very carefully solvent tooth brush until can wipe surface white cotton sheet come clean same above believe proper pis ton/sleeve clearance essential before running experience indicates too-tight fit will result harder piston pushing brass sleeve deforming necessary achieve running fit have unable extract maximum perform ance happens Its difficult de termine exact clearance required prior running lap free run engine carefully briefly Remove head carefully examine chrome surface sleeve observe extra shiny areas especially top stroke fit still tight Extra lapping special proce dures such honing machine lapping can used correct problem Ringed Piston piston ring utmost importance must absolutely round have small gap possible remain round installed piston conditions exception rather rule basic problem establish perfectly round paralleled bore sleeve Since dont have piston lap can take chance having true sleeve make lap cant machine shop can machine bar brass aluminum bare slip fit sleeve Given true sleeve smear light coat compound sleeve place rings between two piston skirts similar tight fitting cylinders lap rings sleeve Lap little first clean examine ring rubbing surface polish Lap until truly important small ring gap round ring will develop power regardless gap size final test push ring sleeve squarely hold up product review product review product review Wing Cutout Tool better mousetrap cate gory Groovers provide effective answer nuisance problem cutting out foam ser vos landing gear retract wells ailerons torque tubes etc Preformed wire cutters fit gun-type soldering irons Die-cut templates includedl make such chores snap Anon Enterprises also offers over 60 different foam wing cores almost popular RC ma chine can think including flying lawnmower molded wheels Firm has over 500 plans templates will quote plan Also has Doods nylon mounting bolt sets speed wrench threaded wood block Anion Enterprises PO Box 337 Hwy 56 West Edgerton KS 66021 Lapped ABC procedure essentially product review product review product review light look signs light between ring sleeve No light round ring Install ring piston carefully Cylinder Sleeve Ive always put dab compound under lip sleeve rotated crankcase sure lower surface sleeve lip matched mating surface top case Cylinder Head Same above dab compound mate both surfaces regard less gasket may supplied engine careful lap head bore surface sleeve tight fit tween head sleeve essential Back Cover Lap back cover rear mating surface case Cleaning Assembly Recheck parts sure absolutely clean Oil lightly 3-in-l oil assemble engine Tighten opposite screws little time turn crankshaft after part installed sure finally put glow plug flip prop will know difference engine will loose compression seal will surprise Final Examination Wipe external sur faces clean look signs oil leaking past sealing surfaces everything okay store engine plastic bag until ready run test stand Conclusion Development basic skills preparing engine run essen tial discussion intended get modelers started dont already pre pare engines will enjoy acquiring skills needed understand seemingly small details have substantial effect engine performance Next month well run engine test stand Don Jehlik 438A Schweer Dr Star Route 1 Hawthorne NV 89415 Scale Model/Preston continued page 55 falls napalm types excepted expect score 10 points Another scale operation may think dead giveaway operation flaps have received both tens zeros flap demonstrations Monocoupe zero awarded judge claimed able see flaps move during flight after cycled down up four times during flight takeoff missed approach separate flap demo landing am now reluctant use flaps option still use landings since trim change nose up advantageous keeping model nosing over during landing though may elect use flaps lieu flying maneuver may 100 Model Aviation FAMOUS BRITISH DIESELS D/C PAW M/E rj * *NEW* * CATALOG-DIESEL HANDBOOK $150 pp HOBBY HIDEAWAY DELAVANILL61734 MORRISONSCALE DRAWINGS EPLA TECHCATALOG 25c ntefl10t 01W 40500 McKenzie Hwy vida Oregon 97450