Beckman Kirby Crawford hi ban ersfo Part Three series power plants big uns Bob Kirby discuss five engines range smallest about biggest gasoline-burners THIS INSTALLMENT covers almost entire size range Big Bird gasoline burners 12 Cu fl MagAerotoa48 Cu special order engine Roush Mfg interesting note both engines based Kioritz products between extremes look three engines Roper Husky Kawasaki Refer Part 1 series April 81 Model Aviation description test equipment procedures has significant addition test equipment beginning have doubts about venerable old Heathkit Thumb Tach Now thanks Dick Penrod Giezen danner USA have use Giezendanner Digital Tachometers device easier read much accurate addition helped us identify rather embarrassing error original setup Bobs old Thumb Tach used several years instruction book long gone checked agalnst incandescent light 3000 rpm reading seemed correctdue faulty memory little thought would have realized should have 3600 until read instructions Digital Tach mistake became obvious cross-checking between two find multiplying Thumb Tach readings 12 yields same reading Giezendanner unit within rpm accuracy Thumb Tach itself previously published rpm D TZTZZDTZDTZ TZ KTZD T 15-61164 165 166 16-6 16-8 186 18-6 186 18-8 18-8 18-8 18-10 18-10 20-5 204 20-6 20-8 20-8 RPM 1900 1900 1900 1800 1800 f7 i T T7 1700 1700 1600 1600 1600 1600 1400 1800 1800 mu Top RPM 7350 18400 73006900 6850 6300 5600 6200 5800 5600 5600 5800 4950 5300 5500 5000 5600 5200 4600 Lb Thrust 65775 75 8825 8 55 10 5 10 9510 le RPM See Rorer Ntes Top RPMIOOOU G1009600940087007150840076007400710072006000650070006200700063506550 rust 145 135 16155 155 1614175 16145 16151415155 155 165 155 15 RPM 2500 2600 2500 2500 2600 2500 2400 2200 2500 2300 2600 2300 2100 EEL RPM 00 8500 3000 8000 8400 7400 8400 7300 7200 hrust18 205 201719195 185 185 202020195 2 RPMDDynathrustGGrish 2200 2200 23002000 2000 Top RPMKKoIboTTop FlitsZZinger8250 8900 8100 8550 7800 7500 rust-2353525562 28 Model Aviation smaii DUT impressive Mag-Aero Hywneel maaneto onints arm innida thin mar hounino Digital Tachometerfrum iaIeunuanner UM vaiuaoieaooiion tfl projects gear Headout units 100 rpm point prop move around until steady reading obtained ins HOPC 19 purrsawayon tuel consumption test run lumberyard props front Data charts continued next page figures should adjusted Please accept apologies inconvenience Note thrust figures affected valid published accuracy digital readout Giezen danner tach make possible get closer rpm readings tach reads hundreds stable enough allow interpolation mid point between readings example steady reading 54 means 5400 rpm reading changing back forth between 54 55 can read 5450 rpm tach easy enough use simply turn point toward propeller vary position until steady reading obtained best position will depend light conditions pleased tachs operation feel valuable addition project mail talking other modelers seems lot people trying use engines understand basics spark ignition Thats understandable since several generations modelers have never used anything glow engines models complete discussion Prop hub YesMuffler Noexhaust stack supplied Other 90-dog throttle linkage Additional items requird excluding prop fuel tank None Recommended propeller 18-6 Recommended fuei mix 201 Carburetor Make type Waibrodiaphram pump Controls availabie Throttle Adjustments avali idle set screw high low speed mixture ignitionType Magneto mechanical points Spark plug Champion RCJ8 Recommended gap specified Magneto gap specified Point gap specified Kill disable system Magneto grounding wire Internal details induction Direct piston porting Cyiinder Die cast aluminumchromed Piston rings High silicon content aiuminum 2 iron rings Crankshaft Forged steel Bearings Ball bearing front rear Conrod Forged steel Bearings Needle bearings both ends Dimensions Orientation dimensions looking forward along crankshaft upright engine Prop refers propeller back side 1 Firewall prop mount supplied 7-1/8 2 Prop reermost point excluding rear shaft 7 rear housing 3 Prop forwardmost point /4 plug 4 Maximum extension thrust line 4-1/8 top cylinder @ 3-3/4 behind prop 5 Vertical dimensions thrust line a Up 4-1/8 top cylinder 0 3-3/4 behind prop b Down 2-3/16 throttle belicrank bracket @ 4-1/16 behind prop 6 Horizontal extension thrust line 3-38 carb 0 2 behind prop 7 Propeller hub diameter 1-3/8 Bolt hole diameter NA 8 Propeller washer 1-1/32 dia aluminum 9 Mounting bolt pattern 2-7/8 sq shaft center Subjective items following beyond ability measure di rectly offered opinions what worth 1 Overall appearance High quality beautiful workmanship unusual layout 2 Amount quality instructions Adequate clearly written 3 Ease starting a Cold Super excellent 5 6 flips b Hot delightfirst flip usually 4 Ease mounting control hook-up Simple radial mount straightforward hook-up 5 Ease carburetor adjustments Awkward engine running 6 Vibration levels Super smooth - 7 Cowlabillty Plug carb positions can give trouble in4lnetype cowls 8 Crankshaft bearIng slop None subject beyond scope series does seem appropriate point out some simple adjustments necessary proper opera tion spark ignition engine Stated simply possible compressed charge gasoline air cylinder ignited spark jumping between electrodes spark plug spark produced high voltage generated magneto coil timed either mechanical points electronic circuit energy required produced magnets flywheel passing close pole pieces magneto exception electronic ignition circuit things involve gaps proper adjustment various gaps vital operation engine will note data sheets have published include settings An essential tool Big Banger user set ignition feeler gauges avallable auto parts store Lets take look different gaps starting spark plug plug gap affects amount spark produced small extent exact timing will occur gap usually supposed order 0025 0035 points opened closed cam crankshaft points open high tension produced causes spark spark plug Points adjusted positioning crankshaft until points open varying size opening setting can have great effect engine operation Continued page 111 ZDTFTTZTUZGZ2GZZZZ Prop 20121224122422-8 22-10 22-10 22-12 22-14 24-6 24-8 248 24-12 24-14 2416En inc 20-1022-8 [v32][b-1-10-1-10]] 20-B20-1020-10 1600 15001400 1500 IdIRPM 0 2300 IdieRPM 4600 4000 3500 3800 Top RPM tu 5100T RPM P 95875 775 Lb Thrust ~ 335 295 Lb Thrust RPM 00 5000 5050 5250 Top RPM hrust 3513514 e RPMZ 2100 1900 2000 2000 1800 2000 2100 1900 1900 1800 180020001800 72006600 54006500590070007200600061005400560062005800 ~TopR 201918520162020520201617520185ibThrust 18001800190018001900190017001800170017001600 16001700170017001700170014RPM 760071507150720063507400765068007150640064005400530069505800630053504800Top RPM 6265 262727j28 29 27245 rustU st 1981 29 K-21A ENGINE DATA ilent 128 cu iii 21cc CoPrice $16995 Availability Direct & dealers 8249 MIg Klorltz Japan werWeight 4 lb 6 oz mci mount TA SUMMARY ant 1025 lb rpm Kolbo 20-5 prop 201 062 oz/mln fuel consumption supplied Engine mount Yes ne ug d Bob Kirby think probably smoothestrunning engine have tested far Anything RiC W3029 Hoffman Spokane WA 99205 W L Langford 510 Girard Ave Dothan AL 36303 G & G Electronics 497 Central Ave See konk MA 02771 Fred Morgan Box 8516 Cave Creek Stage 28238 N 44th St Phoenix AZ 85020 Ace Service Center Box 511 203 W 19th Higginsville MO 64037 Dundas Hobby Supply 16 Sleepy Hollow Dundas Ont Canada L9H 1H3 Donald J Wadella Dons Radio Control Systems 11392 74th Ave Delta BC Can ada V4C lEl R K Specialties 406 Prospect Dr SW Medicine Hat Alberta Canada TiA 4C1 Mastercraft 4 Linden Rd Chiselhurst Ext East London 5201 South Africa Keep letters flowing dont ask find parts please George M Myers 70 Froehlich Farm Rd Hicksville NY 11801 Big Bangers/Beckman Continued page 29 points never open never close will never spark engine will never run points can set engine runs well should example points too close will stay closed longer should effectively retarding spark engine will lose power especially high speed Points usually set about 0015 fully open magneto air gap should small possible since closer magnets pole pieces go energy will developed spark quality crank shaft bearings size flywheel determine gap needed ensure magnets actually touch go 0010 typical gap chainsaw engines Since gaps mechanical wear vibration can change over period time Periodic adjustment required keep engine running peak performance addition its good idea check things new engine becasue never know what may have happened engine between time left factory time got Listed below additional notes subjective data current set test engines Mag-Aero beautiful engine both fas cinating frustrating Like its big brother Kioritz 24 cu engine extremely well made delight operate first glance seems ideally suited aircraft use turns out have some detracting characteristics large cup-shaped rear housing contains flywheel magneto points As result front engine must less cluttered Big Bangers should make easier cowl Unfortunately position spark plug dictates very flat-faced cowl horizontal protrusion carburetor compli cates mounting in-line cowls Radial cowls would easier extra length engine would require false firewall scale position forward actual firewall engine mounted Despite awkward-seeming layout engine its quality makes outstanding big bird powerplant would particularly useful some Quarter Scale designs originally powered big glow engines Continued page 114 August1981 111 I-NDIAN CITY RADiO CONTROL CLUB mSENTS GREATER MICHIGAN MODELERS SHOW & EXPO ill iS WOATS CAR$ MANLtFACT*J#EES STATIC DI$PLAYSSWAP SHOP 23A 1981 Wt4Rht MI Aftillery Anuaory1 Oak Park MichiR F7 RICKS R/C MODELS IN 81 ITS INTRODUCING THE RICK STICK SUPREMETHE WEEKENDER FLITE BOX SPORTTRAINER- FULLYAEROBATIC SIZE 12% x 12% x 18 IPLYWOOD SANDED READY FOR PRIMER 4 CliCABINET INCLUDED Pro-BuiltSEALER HARDWARE AND 16 DRAWER $8995 Engine 25 40 $4995 Pro-Cut Kit Hardware Landing Gear Full Length Wood md Pre-Built Ready Fine Sand & Cover Full Length Balsa Wood & Spruce Spars Hinged Surfaces Hardware HalIco Gear Nylon Bolts Tapped Bolt Gear & Wing SPACE FOR 15 Drawer Cabinet 1-Gal Fuel Battery Fuel Pump Power Panel Prop Bin Tool Tray Electric Starter Cleaner Towels No Other Like Od. PS Odac NG aede SN lower vibration level Mag-Aero would compatible lighter construction has proven inadequate larger chainsaw engines example Mag-Aero would ideal Piper Cub 12- 14-lb range Another interesting possibility radial engine version Gee Bee Sportster impressed quality easy start ing smooth running engine Roper 19 engine about least ex pensive gasoline burner available Homer Sales offers used factory demo engines $3495 new engines $4995 couple things should clarified however factory referred Roper factory engines new used have modified aircraft use modification difficult can done use machine tools operation outlined instruction sheet comes engine addition doing engine mods will need make buy motor mount prop hub Homer offers both prop hubs made Quadra will fit test engine used demo units Gene Homer already done conversion work Under circumstances skipped usual break-in run went right test runs found backing idle screw out way resulted idle speeds no lower 3000 rpm Since stop arm resting directly screw bracket nothing could field High speed operation affected continued tests discussing engine Gene Homer mentioned could bear start fact instructions recommends using pulley cord possible reason hard starting fairly large magneto air gap required because rather loose needle bear ings crankshaft Once started engine produced credible power its size surprisingly comfort able high speeds low speeds however shaker engine useable reasonable value price Husky 23 several years J C Enterprises has selling converted 2 cu McCulloch chainsaw engine called Husky test engine first new slightly larger version putting market 23 almost identical earlier model except size layout Husky best have seen aircraft application Both carburetor magneto mounted front cylinder instead sticking out side bottom engine makes cowling engine much easier built-in vacuumoperated pump oiling saws chain left engine converted could used smoke system remove pump drill new mounting hole can cut another inch off bottom casting get engine tighter cowls unfortunate difference new engine carb does have built-in choke other hand has larger cooling fins should run little cooler over long periods full throttle feel Husky 23 valuable addition Big Banger list will particu larly useful models in-line cowls Kawasaki TA-5 1 reported smaller Kawasaki engine Part series About can say about same quality beautiful workmanship superb operating characteristics noted earlier report change carburetor mounting resulted much easier adjustment running engine change quite easy work minor surprise fact carb has no idle adjustment screw caused us little difficulty during tests would no problem normal installation use throttle servo set idle Another minor difference between two engines involves rectangular crankcase cast ing removing excess material has little effect weight engines no real effect size smaller model can effect TA-5 1 relocating electronic ignition module trimming casting down magneto about inch can removed could important some cowls its smooth running power output adjustment-free electronic ignition consider Kawasaki outstanding engine Kiorits 48 have complete report engine time felt should make some comments about engine several available Roush Mfg special order basis both larger expensive average modeler will ever want special purpose power plants would out place average flying field other hand have special application facilities handle its nice know power available lot good things about engine pointed out above Husky laid out nicely application engine better carb right smack front cylinder entire ignition system inside flywheel exhaust comes out back course weve learned cope its really nice see engine no 114 Model Aviation Send SASE Free Brochure 0 Oealer Inquiries Invited S Florida Residents Add 4% Sales Tax CHECK OR MO KS R/t MODELS INC Handling ft shiomog 1730 DREW ST CLEARWATER FL 33515 FIightIine shirts have got covered One-liner Shirts sioso Plane Shirts 5725 top quality football shirts complete history back sky blue blue printing war- ground colorful \W/ll birds red printing Pitts airplanes applied sky blue shirts design fine line followed aarowstr aoearoP-3a UgiWilog-korkane FlU-i ConalP-39 NacobraLyandor AF4F WildcatP40 WahawkSpitfiw F6F I-lelicatP47 ThondebosTyphoon profile view classic airplane F7F TigewatP-Si PAatanga 17 Aylng Fote FBF BearcatPM Black Widow5-24 LIberator crie ui riurrIur d luL people Sky blue T-shirts printed two colors Pitts shirt white printed red black ~auIiSfl1uaee Mens sizes Sm 132-361 Med 38-40J Lg 142441 XL 1461 OdPP NameSend check money order Iplus SI P/HI AddressFlIghtilne Shirts EtcAdd 65% taX california 12504 Saratoga AvenueSend SASS CityStateZipSaratoga CA 95070 bWdOe SizeStyleDesignTotal SIAiiow 4-6 weeks delivelyl Machine-shaped balsa plywood hardwood Die-cut ribs constant chord wing Dursi main landing gear tricycle gear Hardware package nuts bolts control RAPIER s nose-gear bearing Fuel tank size 10 oz 12 oz Flying weight 6 lb Wingspan 57 Wing area 752 sq Wing chord 13 SPECIFICATIONSFuselage 48 Build 15 hours gentle tlyer wIth a40 great sport tlyer a60 Semi-symmetrical wing long moment big plane responsive tlyer tully aerobatic Four-channel radio engine elevator rudder Complete building instruction booklet Basic materials balsa plywood2657 N 6 188th Street selected hardwoodsMam Ftoda 33180 TelepSone 935-1436 wider flywheel would great would just engine size Quadra 24 Kioritz engine comes larger Kioritz professional chainsaws Roush brothers have done beautiful job converting aircraft use understand inquiries about other large engines coming people building micro-lights powered hang gliders Roush can supply engines up 5 6 dil reason have little operational data engine difficulty getting run engine has fairly high compression starting procedure somewhat different what have using first session engine resulted run mainly because werent doing things right next weekend little luck getting started first time ran some ignition problems decided hold off until could get ourselves sorted out reporting what can now will add operating data get interested using engine selves impressed Like Kioritz products very high quality conversion work match consider start ing problems due own lack familiarity level engine size wish thank following firms assistance part Big Banger project GB Associates Inc 21658 Cloud Way Hay ward CA 94545 Kawasaki Dynathrust Props Inc 2541 NE 11th Ct, Pompano Beach FL 33062 Giezendanner USA P0 Box 818 Pottatown PA 19464 Grish Bros St John IN 46373 Homer Sales Inc 300 Dixie Hwy Beecher IL 60401 Roper JC Enterprises 2251 SW 28th Terrace Ft Lauderdale FL 33312 Husky Mag-Aero Mfg Co P0 Box 490 Freeland WA 98249 Roush Mfg P0 Box 251 Sandyville OH 44671 Kioritz Top Flite Models Inc 1901 Narragansett Ave Chicago IL 60639 J & Z Products 25029 S Vermont Ave Harbor City CA 90710 Zinger SAFE FLYING IS NO ACCIDENT Scaling Palumbo Continued page 33 force centrifugal force Centrifugal force will exist model moving along straight flight path magnitude centrifugal force equal weightW times velocity V squared divided radius R maneuver times earths gravitational acceleration g32 ft/sec/sec math ematical formula maneuver force therefore WV2 M gR Equation 1 ratio M W simply V2/gR use lower-case letters denote models velocity maneuver radius ratio v2/gr model Equating full-size airplanes ratio models ratio MIW m/w obtain V2_ v2 R r Equation 2 because g common both Now lets assume models scale factor number denoted N model manuever within scale airspace must maneuver within scale its dimensions Hence maneuver radius model should scaled accordance models scale factor mathematically means r Substituting R Equation 2 gives V Equation 3 establishes relationship between models speed speed full-size airplane necessary ensure model will perform within scale airspace Note since distance has scaled directly N velocity distance divided time can now seen full-size airplanes time frame stretched square root N compared models time frame As example full-size airplane performing 600-ft diameter loop average speed 150 mph would scale 1/6-size model performing 100-ft diameter loop average speed 61 mph would take 86 seconds full-size airplane complete loop 35 seconds model complete itslp formula Eq 3 presented graphically Fig 2 variety scale factors mathematically inclined aerodynamic forces airplane lift drag direct proportion air density wing area square velocity proportionality constant called force coefficient Mathematically CA$V2S August1981 115 h-L1~at is
Edition: Model Aviation - 1981/08
Page Numbers: 28, 29, 111, 114, 115
Beckman Kirby Crawford hi ban ersfo Part Three series power plants big uns Bob Kirby discuss five engines range smallest about biggest gasoline-burners THIS INSTALLMENT covers almost entire size range Big Bird gasoline burners 12 Cu fl MagAerotoa48 Cu special order engine Roush Mfg interesting note both engines based Kioritz products between extremes look three engines Roper Husky Kawasaki Refer Part 1 series April 81 Model Aviation description test equipment procedures has significant addition test equipment beginning have doubts about venerable old Heathkit Thumb Tach Now thanks Dick Penrod Giezen danner USA have use Giezendanner Digital Tachometers device easier read much accurate addition helped us identify rather embarrassing error original setup Bobs old Thumb Tach used several years instruction book long gone checked agalnst incandescent light 3000 rpm reading seemed correctdue faulty memory little thought would have realized should have 3600 until read instructions Digital Tach mistake became obvious cross-checking between two find multiplying Thumb Tach readings 12 yields same reading Giezendanner unit within rpm accuracy Thumb Tach itself previously published rpm D TZTZZDTZDTZ TZ KTZD T 15-61164 165 166 16-6 16-8 186 18-6 186 18-8 18-8 18-8 18-10 18-10 20-5 204 20-6 20-8 20-8 RPM 1900 1900 1900 1800 1800 f7 i T T7 1700 1700 1600 1600 1600 1600 1400 1800 1800 mu Top RPM 7350 18400 73006900 6850 6300 5600 6200 5800 5600 5600 5800 4950 5300 5500 5000 5600 5200 4600 Lb Thrust 65775 75 8825 8 55 10 5 10 9510 le RPM See Rorer Ntes Top RPMIOOOU G1009600940087007150840076007400710072006000650070006200700063506550 rust 145 135 16155 155 1614175 16145 16151415155 155 165 155 15 RPM 2500 2600 2500 2500 2600 2500 2400 2200 2500 2300 2600 2300 2100 EEL RPM 00 8500 3000 8000 8400 7400 8400 7300 7200 hrust18 205 201719195 185 185 202020195 2 RPMDDynathrustGGrish 2200 2200 23002000 2000 Top RPMKKoIboTTop FlitsZZinger8250 8900 8100 8550 7800 7500 rust-2353525562 28 Model Aviation smaii DUT impressive Mag-Aero Hywneel maaneto onints arm innida thin mar hounino Digital Tachometerfrum iaIeunuanner UM vaiuaoieaooiion tfl projects gear Headout units 100 rpm point prop move around until steady reading obtained ins HOPC 19 purrsawayon tuel consumption test run lumberyard props front Data charts continued next page figures should adjusted Please accept apologies inconvenience Note thrust figures affected valid published accuracy digital readout Giezen danner tach make possible get closer rpm readings tach reads hundreds stable enough allow interpolation mid point between readings example steady reading 54 means 5400 rpm reading changing back forth between 54 55 can read 5450 rpm tach easy enough use simply turn point toward propeller vary position until steady reading obtained best position will depend light conditions pleased tachs operation feel valuable addition project mail talking other modelers seems lot people trying use engines understand basics spark ignition Thats understandable since several generations modelers have never used anything glow engines models complete discussion Prop hub YesMuffler Noexhaust stack supplied Other 90-dog throttle linkage Additional items requird excluding prop fuel tank None Recommended propeller 18-6 Recommended fuei mix 201 Carburetor Make type Waibrodiaphram pump Controls availabie Throttle Adjustments avali idle set screw high low speed mixture ignitionType Magneto mechanical points Spark plug Champion RCJ8 Recommended gap specified Magneto gap specified Point gap specified Kill disable system Magneto grounding wire Internal details induction Direct piston porting Cyiinder Die cast aluminumchromed Piston rings High silicon content aiuminum 2 iron rings Crankshaft Forged steel Bearings Ball bearing front rear Conrod Forged steel Bearings Needle bearings both ends Dimensions Orientation dimensions looking forward along crankshaft upright engine Prop refers propeller back side 1 Firewall prop mount supplied 7-1/8 2 Prop reermost point excluding rear shaft 7 rear housing 3 Prop forwardmost point /4 plug 4 Maximum extension thrust line 4-1/8 top cylinder @ 3-3/4 behind prop 5 Vertical dimensions thrust line a Up 4-1/8 top cylinder 0 3-3/4 behind prop b Down 2-3/16 throttle belicrank bracket @ 4-1/16 behind prop 6 Horizontal extension thrust line 3-38 carb 0 2 behind prop 7 Propeller hub diameter 1-3/8 Bolt hole diameter NA 8 Propeller washer 1-1/32 dia aluminum 9 Mounting bolt pattern 2-7/8 sq shaft center Subjective items following beyond ability measure di rectly offered opinions what worth 1 Overall appearance High quality beautiful workmanship unusual layout 2 Amount quality instructions Adequate clearly written 3 Ease starting a Cold Super excellent 5 6 flips b Hot delightfirst flip usually 4 Ease mounting control hook-up Simple radial mount straightforward hook-up 5 Ease carburetor adjustments Awkward engine running 6 Vibration levels Super smooth - 7 Cowlabillty Plug carb positions can give trouble in4lnetype cowls 8 Crankshaft bearIng slop None subject beyond scope series does seem appropriate point out some simple adjustments necessary proper opera tion spark ignition engine Stated simply possible compressed charge gasoline air cylinder ignited spark jumping between electrodes spark plug spark produced high voltage generated magneto coil timed either mechanical points electronic circuit energy required produced magnets flywheel passing close pole pieces magneto exception electronic ignition circuit things involve gaps proper adjustment various gaps vital operation engine will note data sheets have published include settings An essential tool Big Banger user set ignition feeler gauges avallable auto parts store Lets take look different gaps starting spark plug plug gap affects amount spark produced small extent exact timing will occur gap usually supposed order 0025 0035 points opened closed cam crankshaft points open high tension produced causes spark spark plug Points adjusted positioning crankshaft until points open varying size opening setting can have great effect engine operation Continued page 111 ZDTFTTZTUZGZ2GZZZZ Prop 20121224122422-8 22-10 22-10 22-12 22-14 24-6 24-8 248 24-12 24-14 2416En inc 20-1022-8 [v32][b-1-10-1-10]] 20-B20-1020-10 1600 15001400 1500 IdIRPM 0 2300 IdieRPM 4600 4000 3500 3800 Top RPM tu 5100T RPM P 95875 775 Lb Thrust ~ 335 295 Lb Thrust RPM 00 5000 5050 5250 Top RPM hrust 3513514 e RPMZ 2100 1900 2000 2000 1800 2000 2100 1900 1900 1800 180020001800 72006600 54006500590070007200600061005400560062005800 ~TopR 201918520162020520201617520185ibThrust 18001800190018001900190017001800170017001600 16001700170017001700170014RPM 760071507150720063507400765068007150640064005400530069505800630053504800Top RPM 6265 262727j28 29 27245 rustU st 1981 29 K-21A ENGINE DATA ilent 128 cu iii 21cc CoPrice $16995 Availability Direct & dealers 8249 MIg Klorltz Japan werWeight 4 lb 6 oz mci mount TA SUMMARY ant 1025 lb rpm Kolbo 20-5 prop 201 062 oz/mln fuel consumption supplied Engine mount Yes ne ug d Bob Kirby think probably smoothestrunning engine have tested far Anything RiC W3029 Hoffman Spokane WA 99205 W L Langford 510 Girard Ave Dothan AL 36303 G & G Electronics 497 Central Ave See konk MA 02771 Fred Morgan Box 8516 Cave Creek Stage 28238 N 44th St Phoenix AZ 85020 Ace Service Center Box 511 203 W 19th Higginsville MO 64037 Dundas Hobby Supply 16 Sleepy Hollow Dundas Ont Canada L9H 1H3 Donald J Wadella Dons Radio Control Systems 11392 74th Ave Delta BC Can ada V4C lEl R K Specialties 406 Prospect Dr SW Medicine Hat Alberta Canada TiA 4C1 Mastercraft 4 Linden Rd Chiselhurst Ext East London 5201 South Africa Keep letters flowing dont ask find parts please George M Myers 70 Froehlich Farm Rd Hicksville NY 11801 Big Bangers/Beckman Continued page 29 points never open never close will never spark engine will never run points can set engine runs well should example points too close will stay closed longer should effectively retarding spark engine will lose power especially high speed Points usually set about 0015 fully open magneto air gap should small possible since closer magnets pole pieces go energy will developed spark quality crank shaft bearings size flywheel determine gap needed ensure magnets actually touch go 0010 typical gap chainsaw engines Since gaps mechanical wear vibration can change over period time Periodic adjustment required keep engine running peak performance addition its good idea check things new engine becasue never know what may have happened engine between time left factory time got Listed below additional notes subjective data current set test engines Mag-Aero beautiful engine both fas cinating frustrating Like its big brother Kioritz 24 cu engine extremely well made delight operate first glance seems ideally suited aircraft use turns out have some detracting characteristics large cup-shaped rear housing contains flywheel magneto points As result front engine must less cluttered Big Bangers should make easier cowl Unfortunately position spark plug dictates very flat-faced cowl horizontal protrusion carburetor compli cates mounting in-line cowls Radial cowls would easier extra length engine would require false firewall scale position forward actual firewall engine mounted Despite awkward-seeming layout engine its quality makes outstanding big bird powerplant would particularly useful some Quarter Scale designs originally powered big glow engines Continued page 114 August1981 111 I-NDIAN CITY RADiO CONTROL CLUB mSENTS GREATER MICHIGAN MODELERS SHOW & EXPO ill iS WOATS CAR$ MANLtFACT*J#EES STATIC DI$PLAYSSWAP SHOP 23A 1981 Wt4Rht MI Aftillery Anuaory1 Oak Park MichiR F7 RICKS R/C MODELS IN 81 ITS INTRODUCING THE RICK STICK SUPREMETHE WEEKENDER FLITE BOX SPORTTRAINER- FULLYAEROBATIC SIZE 12% x 12% x 18 IPLYWOOD SANDED READY FOR PRIMER 4 CliCABINET INCLUDED Pro-BuiltSEALER HARDWARE AND 16 DRAWER $8995 Engine 25 40 $4995 Pro-Cut Kit Hardware Landing Gear Full Length Wood md Pre-Built Ready Fine Sand & Cover Full Length Balsa Wood & Spruce Spars Hinged Surfaces Hardware HalIco Gear Nylon Bolts Tapped Bolt Gear & Wing SPACE FOR 15 Drawer Cabinet 1-Gal Fuel Battery Fuel Pump Power Panel Prop Bin Tool Tray Electric Starter Cleaner Towels No Other Like Od. PS Odac NG aede SN lower vibration level Mag-Aero would compatible lighter construction has proven inadequate larger chainsaw engines example Mag-Aero would ideal Piper Cub 12- 14-lb range Another interesting possibility radial engine version Gee Bee Sportster impressed quality easy start ing smooth running engine Roper 19 engine about least ex pensive gasoline burner available Homer Sales offers used factory demo engines $3495 new engines $4995 couple things should clarified however factory referred Roper factory engines new used have modified aircraft use modification difficult can done use machine tools operation outlined instruction sheet comes engine addition doing engine mods will need make buy motor mount prop hub Homer offers both prop hubs made Quadra will fit test engine used demo units Gene Homer already done conversion work Under circumstances skipped usual break-in run went right test runs found backing idle screw out way resulted idle speeds no lower 3000 rpm Since stop arm resting directly screw bracket nothing could field High speed operation affected continued tests discussing engine Gene Homer mentioned could bear start fact instructions recommends using pulley cord possible reason hard starting fairly large magneto air gap required because rather loose needle bear ings crankshaft Once started engine produced credible power its size surprisingly comfort able high speeds low speeds however shaker engine useable reasonable value price Husky 23 several years J C Enterprises has selling converted 2 cu McCulloch chainsaw engine called Husky test engine first new slightly larger version putting market 23 almost identical earlier model except size layout Husky best have seen aircraft application Both carburetor magneto mounted front cylinder instead sticking out side bottom engine makes cowling engine much easier built-in vacuumoperated pump oiling saws chain left engine converted could used smoke system remove pump drill new mounting hole can cut another inch off bottom casting get engine tighter cowls unfortunate difference new engine carb does have built-in choke other hand has larger cooling fins should run little cooler over long periods full throttle feel Husky 23 valuable addition Big Banger list will particu larly useful models in-line cowls Kawasaki TA-5 1 reported smaller Kawasaki engine Part series About can say about same quality beautiful workmanship superb operating characteristics noted earlier report change carburetor mounting resulted much easier adjustment running engine change quite easy work minor surprise fact carb has no idle adjustment screw caused us little difficulty during tests would no problem normal installation use throttle servo set idle Another minor difference between two engines involves rectangular crankcase cast ing removing excess material has little effect weight engines no real effect size smaller model can effect TA-5 1 relocating electronic ignition module trimming casting down magneto about inch can removed could important some cowls its smooth running power output adjustment-free electronic ignition consider Kawasaki outstanding engine Kiorits 48 have complete report engine time felt should make some comments about engine several available Roush Mfg special order basis both larger expensive average modeler will ever want special purpose power plants would out place average flying field other hand have special application facilities handle its nice know power available lot good things about engine pointed out above Husky laid out nicely application engine better carb right smack front cylinder entire ignition system inside flywheel exhaust comes out back course weve learned cope its really nice see engine no 114 Model Aviation Send SASE Free Brochure 0 Oealer Inquiries Invited S Florida Residents Add 4% Sales Tax CHECK OR MO KS R/t MODELS INC Handling ft shiomog 1730 DREW ST CLEARWATER FL 33515 FIightIine shirts have got covered One-liner Shirts sioso Plane Shirts 5725 top quality football shirts complete history back sky blue blue printing war- ground colorful \W/ll birds red printing Pitts airplanes applied sky blue shirts design fine line followed aarowstr aoearoP-3a UgiWilog-korkane FlU-i ConalP-39 NacobraLyandor AF4F WildcatP40 WahawkSpitfiw F6F I-lelicatP47 ThondebosTyphoon profile view classic airplane F7F TigewatP-Si PAatanga 17 Aylng Fote FBF BearcatPM Black Widow5-24 LIberator crie ui riurrIur d luL people Sky blue T-shirts printed two colors Pitts shirt white printed red black ~auIiSfl1uaee Mens sizes Sm 132-361 Med 38-40J Lg 142441 XL 1461 OdPP NameSend check money order Iplus SI P/HI AddressFlIghtilne Shirts EtcAdd 65% taX california 12504 Saratoga AvenueSend SASS CityStateZipSaratoga CA 95070 bWdOe SizeStyleDesignTotal SIAiiow 4-6 weeks delivelyl Machine-shaped balsa plywood hardwood Die-cut ribs constant chord wing Dursi main landing gear tricycle gear Hardware package nuts bolts control RAPIER s nose-gear bearing Fuel tank size 10 oz 12 oz Flying weight 6 lb Wingspan 57 Wing area 752 sq Wing chord 13 SPECIFICATIONSFuselage 48 Build 15 hours gentle tlyer wIth a40 great sport tlyer a60 Semi-symmetrical wing long moment big plane responsive tlyer tully aerobatic Four-channel radio engine elevator rudder Complete building instruction booklet Basic materials balsa plywood2657 N 6 188th Street selected hardwoodsMam Ftoda 33180 TelepSone 935-1436 wider flywheel would great would just engine size Quadra 24 Kioritz engine comes larger Kioritz professional chainsaws Roush brothers have done beautiful job converting aircraft use understand inquiries about other large engines coming people building micro-lights powered hang gliders Roush can supply engines up 5 6 dil reason have little operational data engine difficulty getting run engine has fairly high compression starting procedure somewhat different what have using first session engine resulted run mainly because werent doing things right next weekend little luck getting started first time ran some ignition problems decided hold off until could get ourselves sorted out reporting what can now will add operating data get interested using engine selves impressed Like Kioritz products very high quality conversion work match consider start ing problems due own lack familiarity level engine size wish thank following firms assistance part Big Banger project GB Associates Inc 21658 Cloud Way Hay ward CA 94545 Kawasaki Dynathrust Props Inc 2541 NE 11th Ct, Pompano Beach FL 33062 Giezendanner USA P0 Box 818 Pottatown PA 19464 Grish Bros St John IN 46373 Homer Sales Inc 300 Dixie Hwy Beecher IL 60401 Roper JC Enterprises 2251 SW 28th Terrace Ft Lauderdale FL 33312 Husky Mag-Aero Mfg Co P0 Box 490 Freeland WA 98249 Roush Mfg P0 Box 251 Sandyville OH 44671 Kioritz Top Flite Models Inc 1901 Narragansett Ave Chicago IL 60639 J & Z Products 25029 S Vermont Ave Harbor City CA 90710 Zinger SAFE FLYING IS NO ACCIDENT Scaling Palumbo Continued page 33 force centrifugal force Centrifugal force will exist model moving along straight flight path magnitude centrifugal force equal weightW times velocity V squared divided radius R maneuver times earths gravitational acceleration g32 ft/sec/sec math ematical formula maneuver force therefore WV2 M gR Equation 1 ratio M W simply V2/gR use lower-case letters denote models velocity maneuver radius ratio v2/gr model Equating full-size airplanes ratio models ratio MIW m/w obtain V2_ v2 R r Equation 2 because g common both Now lets assume models scale factor number denoted N model manuever within scale airspace must maneuver within scale its dimensions Hence maneuver radius model should scaled accordance models scale factor mathematically means r Substituting R Equation 2 gives V Equation 3 establishes relationship between models speed speed full-size airplane necessary ensure model will perform within scale airspace Note since distance has scaled directly N velocity distance divided time can now seen full-size airplanes time frame stretched square root N compared models time frame As example full-size airplane performing 600-ft diameter loop average speed 150 mph would scale 1/6-size model performing 100-ft diameter loop average speed 61 mph would take 86 seconds full-size airplane complete loop 35 seconds model complete itslp formula Eq 3 presented graphically Fig 2 variety scale factors mathematically inclined aerodynamic forces airplane lift drag direct proportion air density wing area square velocity proportionality constant called force coefficient Mathematically CA$V2S August1981 115 h-L1~at is
Edition: Model Aviation - 1981/08
Page Numbers: 28, 29, 111, 114, 115
Beckman Kirby Crawford hi ban ersfo Part Three series power plants big uns Bob Kirby discuss five engines range smallest about biggest gasoline-burners THIS INSTALLMENT covers almost entire size range Big Bird gasoline burners 12 Cu fl MagAerotoa48 Cu special order engine Roush Mfg interesting note both engines based Kioritz products between extremes look three engines Roper Husky Kawasaki Refer Part 1 series April 81 Model Aviation description test equipment procedures has significant addition test equipment beginning have doubts about venerable old Heathkit Thumb Tach Now thanks Dick Penrod Giezen danner USA have use Giezendanner Digital Tachometers device easier read much accurate addition helped us identify rather embarrassing error original setup Bobs old Thumb Tach used several years instruction book long gone checked agalnst incandescent light 3000 rpm reading seemed correctdue faulty memory little thought would have realized should have 3600 until read instructions Digital Tach mistake became obvious cross-checking between two find multiplying Thumb Tach readings 12 yields same reading Giezendanner unit within rpm accuracy Thumb Tach itself previously published rpm D TZTZZDTZDTZ TZ KTZD T 15-61164 165 166 16-6 16-8 186 18-6 186 18-8 18-8 18-8 18-10 18-10 20-5 204 20-6 20-8 20-8 RPM 1900 1900 1900 1800 1800 f7 i T T7 1700 1700 1600 1600 1600 1600 1400 1800 1800 mu Top RPM 7350 18400 73006900 6850 6300 5600 6200 5800 5600 5600 5800 4950 5300 5500 5000 5600 5200 4600 Lb Thrust 65775 75 8825 8 55 10 5 10 9510 le RPM See Rorer Ntes Top RPMIOOOU G1009600940087007150840076007400710072006000650070006200700063506550 rust 145 135 16155 155 1614175 16145 16151415155 155 165 155 15 RPM 2500 2600 2500 2500 2600 2500 2400 2200 2500 2300 2600 2300 2100 EEL RPM 00 8500 3000 8000 8400 7400 8400 7300 7200 hrust18 205 201719195 185 185 202020195 2 RPMDDynathrustGGrish 2200 2200 23002000 2000 Top RPMKKoIboTTop FlitsZZinger8250 8900 8100 8550 7800 7500 rust-2353525562 28 Model Aviation smaii DUT impressive Mag-Aero Hywneel maaneto onints arm innida thin mar hounino Digital Tachometerfrum iaIeunuanner UM vaiuaoieaooiion tfl projects gear Headout units 100 rpm point prop move around until steady reading obtained ins HOPC 19 purrsawayon tuel consumption test run lumberyard props front Data charts continued next page figures should adjusted Please accept apologies inconvenience Note thrust figures affected valid published accuracy digital readout Giezen danner tach make possible get closer rpm readings tach reads hundreds stable enough allow interpolation mid point between readings example steady reading 54 means 5400 rpm reading changing back forth between 54 55 can read 5450 rpm tach easy enough use simply turn point toward propeller vary position until steady reading obtained best position will depend light conditions pleased tachs operation feel valuable addition project mail talking other modelers seems lot people trying use engines understand basics spark ignition Thats understandable since several generations modelers have never used anything glow engines models complete discussion Prop hub YesMuffler Noexhaust stack supplied Other 90-dog throttle linkage Additional items requird excluding prop fuel tank None Recommended propeller 18-6 Recommended fuei mix 201 Carburetor Make type Waibrodiaphram pump Controls availabie Throttle Adjustments avali idle set screw high low speed mixture ignitionType Magneto mechanical points Spark plug Champion RCJ8 Recommended gap specified Magneto gap specified Point gap specified Kill disable system Magneto grounding wire Internal details induction Direct piston porting Cyiinder Die cast aluminumchromed Piston rings High silicon content aiuminum 2 iron rings Crankshaft Forged steel Bearings Ball bearing front rear Conrod Forged steel Bearings Needle bearings both ends Dimensions Orientation dimensions looking forward along crankshaft upright engine Prop refers propeller back side 1 Firewall prop mount supplied 7-1/8 2 Prop reermost point excluding rear shaft 7 rear housing 3 Prop forwardmost point /4 plug 4 Maximum extension thrust line 4-1/8 top cylinder @ 3-3/4 behind prop 5 Vertical dimensions thrust line a Up 4-1/8 top cylinder 0 3-3/4 behind prop b Down 2-3/16 throttle belicrank bracket @ 4-1/16 behind prop 6 Horizontal extension thrust line 3-38 carb 0 2 behind prop 7 Propeller hub diameter 1-3/8 Bolt hole diameter NA 8 Propeller washer 1-1/32 dia aluminum 9 Mounting bolt pattern 2-7/8 sq shaft center Subjective items following beyond ability measure di rectly offered opinions what worth 1 Overall appearance High quality beautiful workmanship unusual layout 2 Amount quality instructions Adequate clearly written 3 Ease starting a Cold Super excellent 5 6 flips b Hot delightfirst flip usually 4 Ease mounting control hook-up Simple radial mount straightforward hook-up 5 Ease carburetor adjustments Awkward engine running 6 Vibration levels Super smooth - 7 Cowlabillty Plug carb positions can give trouble in4lnetype cowls 8 Crankshaft bearIng slop None subject beyond scope series does seem appropriate point out some simple adjustments necessary proper opera tion spark ignition engine Stated simply possible compressed charge gasoline air cylinder ignited spark jumping between electrodes spark plug spark produced high voltage generated magneto coil timed either mechanical points electronic circuit energy required produced magnets flywheel passing close pole pieces magneto exception electronic ignition circuit things involve gaps proper adjustment various gaps vital operation engine will note data sheets have published include settings An essential tool Big Banger user set ignition feeler gauges avallable auto parts store Lets take look different gaps starting spark plug plug gap affects amount spark produced small extent exact timing will occur gap usually supposed order 0025 0035 points opened closed cam crankshaft points open high tension produced causes spark spark plug Points adjusted positioning crankshaft until points open varying size opening setting can have great effect engine operation Continued page 111 ZDTFTTZTUZGZ2GZZZZ Prop 20121224122422-8 22-10 22-10 22-12 22-14 24-6 24-8 248 24-12 24-14 2416En inc 20-1022-8 [v32][b-1-10-1-10]] 20-B20-1020-10 1600 15001400 1500 IdIRPM 0 2300 IdieRPM 4600 4000 3500 3800 Top RPM tu 5100T RPM P 95875 775 Lb Thrust ~ 335 295 Lb Thrust RPM 00 5000 5050 5250 Top RPM hrust 3513514 e RPMZ 2100 1900 2000 2000 1800 2000 2100 1900 1900 1800 180020001800 72006600 54006500590070007200600061005400560062005800 ~TopR 201918520162020520201617520185ibThrust 18001800190018001900190017001800170017001600 16001700170017001700170014RPM 760071507150720063507400765068007150640064005400530069505800630053504800Top RPM 6265 262727j28 29 27245 rustU st 1981 29 K-21A ENGINE DATA ilent 128 cu iii 21cc CoPrice $16995 Availability Direct & dealers 8249 MIg Klorltz Japan werWeight 4 lb 6 oz mci mount TA SUMMARY ant 1025 lb rpm Kolbo 20-5 prop 201 062 oz/mln fuel consumption supplied Engine mount Yes ne ug d Bob Kirby think probably smoothestrunning engine have tested far Anything RiC W3029 Hoffman Spokane WA 99205 W L Langford 510 Girard Ave Dothan AL 36303 G & G Electronics 497 Central Ave See konk MA 02771 Fred Morgan Box 8516 Cave Creek Stage 28238 N 44th St Phoenix AZ 85020 Ace Service Center Box 511 203 W 19th Higginsville MO 64037 Dundas Hobby Supply 16 Sleepy Hollow Dundas Ont Canada L9H 1H3 Donald J Wadella Dons Radio Control Systems 11392 74th Ave Delta BC Can ada V4C lEl R K Specialties 406 Prospect Dr SW Medicine Hat Alberta Canada TiA 4C1 Mastercraft 4 Linden Rd Chiselhurst Ext East London 5201 South Africa Keep letters flowing dont ask find parts please George M Myers 70 Froehlich Farm Rd Hicksville NY 11801 Big Bangers/Beckman Continued page 29 points never open never close will never spark engine will never run points can set engine runs well should example points too close will stay closed longer should effectively retarding spark engine will lose power especially high speed Points usually set about 0015 fully open magneto air gap should small possible since closer magnets pole pieces go energy will developed spark quality crank shaft bearings size flywheel determine gap needed ensure magnets actually touch go 0010 typical gap chainsaw engines Since gaps mechanical wear vibration can change over period time Periodic adjustment required keep engine running peak performance addition its good idea check things new engine becasue never know what may have happened engine between time left factory time got Listed below additional notes subjective data current set test engines Mag-Aero beautiful engine both fas cinating frustrating Like its big brother Kioritz 24 cu engine extremely well made delight operate first glance seems ideally suited aircraft use turns out have some detracting characteristics large cup-shaped rear housing contains flywheel magneto points As result front engine must less cluttered Big Bangers should make easier cowl Unfortunately position spark plug dictates very flat-faced cowl horizontal protrusion carburetor compli cates mounting in-line cowls Radial cowls would easier extra length engine would require false firewall scale position forward actual firewall engine mounted Despite awkward-seeming layout engine its quality makes outstanding big bird powerplant would particularly useful some Quarter Scale designs originally powered big glow engines Continued page 114 August1981 111 I-NDIAN CITY RADiO CONTROL CLUB mSENTS GREATER MICHIGAN MODELERS SHOW & EXPO ill iS WOATS CAR$ MANLtFACT*J#EES STATIC DI$PLAYSSWAP SHOP 23A 1981 Wt4Rht MI Aftillery Anuaory1 Oak Park MichiR F7 RICKS R/C MODELS IN 81 ITS INTRODUCING THE RICK STICK SUPREMETHE WEEKENDER FLITE BOX SPORTTRAINER- FULLYAEROBATIC SIZE 12% x 12% x 18 IPLYWOOD SANDED READY FOR PRIMER 4 CliCABINET INCLUDED Pro-BuiltSEALER HARDWARE AND 16 DRAWER $8995 Engine 25 40 $4995 Pro-Cut Kit Hardware Landing Gear Full Length Wood md Pre-Built Ready Fine Sand & Cover Full Length Balsa Wood & Spruce Spars Hinged Surfaces Hardware HalIco Gear Nylon Bolts Tapped Bolt Gear & Wing SPACE FOR 15 Drawer Cabinet 1-Gal Fuel Battery Fuel Pump Power Panel Prop Bin Tool Tray Electric Starter Cleaner Towels No Other Like Od. PS Odac NG aede SN lower vibration level Mag-Aero would compatible lighter construction has proven inadequate larger chainsaw engines example Mag-Aero would ideal Piper Cub 12- 14-lb range Another interesting possibility radial engine version Gee Bee Sportster impressed quality easy start ing smooth running engine Roper 19 engine about least ex pensive gasoline burner available Homer Sales offers used factory demo engines $3495 new engines $4995 couple things should clarified however factory referred Roper factory engines new used have modified aircraft use modification difficult can done use machine tools operation outlined instruction sheet comes engine addition doing engine mods will need make buy motor mount prop hub Homer offers both prop hubs made Quadra will fit test engine used demo units Gene Homer already done conversion work Under circumstances skipped usual break-in run went right test runs found backing idle screw out way resulted idle speeds no lower 3000 rpm Since stop arm resting directly screw bracket nothing could field High speed operation affected continued tests discussing engine Gene Homer mentioned could bear start fact instructions recommends using pulley cord possible reason hard starting fairly large magneto air gap required because rather loose needle bear ings crankshaft Once started engine produced credible power its size surprisingly comfort able high speeds low speeds however shaker engine useable reasonable value price Husky 23 several years J C Enterprises has selling converted 2 cu McCulloch chainsaw engine called Husky test engine first new slightly larger version putting market 23 almost identical earlier model except size layout Husky best have seen aircraft application Both carburetor magneto mounted front cylinder instead sticking out side bottom engine makes cowling engine much easier built-in vacuumoperated pump oiling saws chain left engine converted could used smoke system remove pump drill new mounting hole can cut another inch off bottom casting get engine tighter cowls unfortunate difference new engine carb does have built-in choke other hand has larger cooling fins should run little cooler over long periods full throttle feel Husky 23 valuable addition Big Banger list will particu larly useful models in-line cowls Kawasaki TA-5 1 reported smaller Kawasaki engine Part series About can say about same quality beautiful workmanship superb operating characteristics noted earlier report change carburetor mounting resulted much easier adjustment running engine change quite easy work minor surprise fact carb has no idle adjustment screw caused us little difficulty during tests would no problem normal installation use throttle servo set idle Another minor difference between two engines involves rectangular crankcase cast ing removing excess material has little effect weight engines no real effect size smaller model can effect TA-5 1 relocating electronic ignition module trimming casting down magneto about inch can removed could important some cowls its smooth running power output adjustment-free electronic ignition consider Kawasaki outstanding engine Kiorits 48 have complete report engine time felt should make some comments about engine several available Roush Mfg special order basis both larger expensive average modeler will ever want special purpose power plants would out place average flying field other hand have special application facilities handle its nice know power available lot good things about engine pointed out above Husky laid out nicely application engine better carb right smack front cylinder entire ignition system inside flywheel exhaust comes out back course weve learned cope its really nice see engine no 114 Model Aviation Send SASE Free Brochure 0 Oealer Inquiries Invited S Florida Residents Add 4% Sales Tax CHECK OR MO KS R/t MODELS INC Handling ft shiomog 1730 DREW ST CLEARWATER FL 33515 FIightIine shirts have got covered One-liner Shirts sioso Plane Shirts 5725 top quality football shirts complete history back sky blue blue printing war- ground colorful \W/ll birds red printing Pitts airplanes applied sky blue shirts design fine line followed aarowstr aoearoP-3a UgiWilog-korkane FlU-i ConalP-39 NacobraLyandor AF4F WildcatP40 WahawkSpitfiw F6F I-lelicatP47 ThondebosTyphoon profile view classic airplane F7F TigewatP-Si PAatanga 17 Aylng Fote FBF BearcatPM Black Widow5-24 LIberator crie ui riurrIur d luL people Sky blue T-shirts printed two colors Pitts shirt white printed red black ~auIiSfl1uaee Mens sizes Sm 132-361 Med 38-40J Lg 142441 XL 1461 OdPP NameSend check money order Iplus SI P/HI AddressFlIghtilne Shirts EtcAdd 65% taX california 12504 Saratoga AvenueSend SASS CityStateZipSaratoga CA 95070 bWdOe SizeStyleDesignTotal SIAiiow 4-6 weeks delivelyl Machine-shaped balsa plywood hardwood Die-cut ribs constant chord wing Dursi main landing gear tricycle gear Hardware package nuts bolts control RAPIER s nose-gear bearing Fuel tank size 10 oz 12 oz Flying weight 6 lb Wingspan 57 Wing area 752 sq Wing chord 13 SPECIFICATIONSFuselage 48 Build 15 hours gentle tlyer wIth a40 great sport tlyer a60 Semi-symmetrical wing long moment big plane responsive tlyer tully aerobatic Four-channel radio engine elevator rudder Complete building instruction booklet Basic materials balsa plywood2657 N 6 188th Street selected hardwoodsMam Ftoda 33180 TelepSone 935-1436 wider flywheel would great would just engine size Quadra 24 Kioritz engine comes larger Kioritz professional chainsaws Roush brothers have done beautiful job converting aircraft use understand inquiries about other large engines coming people building micro-lights powered hang gliders Roush can supply engines up 5 6 dil reason have little operational data engine difficulty getting run engine has fairly high compression starting procedure somewhat different what have using first session engine resulted run mainly because werent doing things right next weekend little luck getting started first time ran some ignition problems decided hold off until could get ourselves sorted out reporting what can now will add operating data get interested using engine selves impressed Like Kioritz products very high quality conversion work match consider start ing problems due own lack familiarity level engine size wish thank following firms assistance part Big Banger project GB Associates Inc 21658 Cloud Way Hay ward CA 94545 Kawasaki Dynathrust Props Inc 2541 NE 11th Ct, Pompano Beach FL 33062 Giezendanner USA P0 Box 818 Pottatown PA 19464 Grish Bros St John IN 46373 Homer Sales Inc 300 Dixie Hwy Beecher IL 60401 Roper JC Enterprises 2251 SW 28th Terrace Ft Lauderdale FL 33312 Husky Mag-Aero Mfg Co P0 Box 490 Freeland WA 98249 Roush Mfg P0 Box 251 Sandyville OH 44671 Kioritz Top Flite Models Inc 1901 Narragansett Ave Chicago IL 60639 J & Z Products 25029 S Vermont Ave Harbor City CA 90710 Zinger SAFE FLYING IS NO ACCIDENT Scaling Palumbo Continued page 33 force centrifugal force Centrifugal force will exist model moving along straight flight path magnitude centrifugal force equal weightW times velocity V squared divided radius R maneuver times earths gravitational acceleration g32 ft/sec/sec math ematical formula maneuver force therefore WV2 M gR Equation 1 ratio M W simply V2/gR use lower-case letters denote models velocity maneuver radius ratio v2/gr model Equating full-size airplanes ratio models ratio MIW m/w obtain V2_ v2 R r Equation 2 because g common both Now lets assume models scale factor number denoted N model manuever within scale airspace must maneuver within scale its dimensions Hence maneuver radius model should scaled accordance models scale factor mathematically means r Substituting R Equation 2 gives V Equation 3 establishes relationship between models speed speed full-size airplane necessary ensure model will perform within scale airspace Note since distance has scaled directly N velocity distance divided time can now seen full-size airplanes time frame stretched square root N compared models time frame As example full-size airplane performing 600-ft diameter loop average speed 150 mph would scale 1/6-size model performing 100-ft diameter loop average speed 61 mph would take 86 seconds full-size airplane complete loop 35 seconds model complete itslp formula Eq 3 presented graphically Fig 2 variety scale factors mathematically inclined aerodynamic forces airplane lift drag direct proportion air density wing area square velocity proportionality constant called force coefficient Mathematically CA$V2S August1981 115 h-L1~at is
Edition: Model Aviation - 1981/08
Page Numbers: 28, 29, 111, 114, 115
Beckman Kirby Crawford hi ban ersfo Part Three series power plants big uns Bob Kirby discuss five engines range smallest about biggest gasoline-burners THIS INSTALLMENT covers almost entire size range Big Bird gasoline burners 12 Cu fl MagAerotoa48 Cu special order engine Roush Mfg interesting note both engines based Kioritz products between extremes look three engines Roper Husky Kawasaki Refer Part 1 series April 81 Model Aviation description test equipment procedures has significant addition test equipment beginning have doubts about venerable old Heathkit Thumb Tach Now thanks Dick Penrod Giezen danner USA have use Giezendanner Digital Tachometers device easier read much accurate addition helped us identify rather embarrassing error original setup Bobs old Thumb Tach used several years instruction book long gone checked agalnst incandescent light 3000 rpm reading seemed correctdue faulty memory little thought would have realized should have 3600 until read instructions Digital Tach mistake became obvious cross-checking between two find multiplying Thumb Tach readings 12 yields same reading Giezendanner unit within rpm accuracy Thumb Tach itself previously published rpm D TZTZZDTZDTZ TZ KTZD T 15-61164 165 166 16-6 16-8 186 18-6 186 18-8 18-8 18-8 18-10 18-10 20-5 204 20-6 20-8 20-8 RPM 1900 1900 1900 1800 1800 f7 i T T7 1700 1700 1600 1600 1600 1600 1400 1800 1800 mu Top RPM 7350 18400 73006900 6850 6300 5600 6200 5800 5600 5600 5800 4950 5300 5500 5000 5600 5200 4600 Lb Thrust 65775 75 8825 8 55 10 5 10 9510 le RPM See Rorer Ntes Top RPMIOOOU G1009600940087007150840076007400710072006000650070006200700063506550 rust 145 135 16155 155 1614175 16145 16151415155 155 165 155 15 RPM 2500 2600 2500 2500 2600 2500 2400 2200 2500 2300 2600 2300 2100 EEL RPM 00 8500 3000 8000 8400 7400 8400 7300 7200 hrust18 205 201719195 185 185 202020195 2 RPMDDynathrustGGrish 2200 2200 23002000 2000 Top RPMKKoIboTTop FlitsZZinger8250 8900 8100 8550 7800 7500 rust-2353525562 28 Model Aviation smaii DUT impressive Mag-Aero Hywneel maaneto onints arm innida thin mar hounino Digital Tachometerfrum iaIeunuanner UM vaiuaoieaooiion tfl projects gear Headout units 100 rpm point prop move around until steady reading obtained ins HOPC 19 purrsawayon tuel consumption test run lumberyard props front Data charts continued next page figures should adjusted Please accept apologies inconvenience Note thrust figures affected valid published accuracy digital readout Giezen danner tach make possible get closer rpm readings tach reads hundreds stable enough allow interpolation mid point between readings example steady reading 54 means 5400 rpm reading changing back forth between 54 55 can read 5450 rpm tach easy enough use simply turn point toward propeller vary position until steady reading obtained best position will depend light conditions pleased tachs operation feel valuable addition project mail talking other modelers seems lot people trying use engines understand basics spark ignition Thats understandable since several generations modelers have never used anything glow engines models complete discussion Prop hub YesMuffler Noexhaust stack supplied Other 90-dog throttle linkage Additional items requird excluding prop fuel tank None Recommended propeller 18-6 Recommended fuei mix 201 Carburetor Make type Waibrodiaphram pump Controls availabie Throttle Adjustments avali idle set screw high low speed mixture ignitionType Magneto mechanical points Spark plug Champion RCJ8 Recommended gap specified Magneto gap specified Point gap specified Kill disable system Magneto grounding wire Internal details induction Direct piston porting Cyiinder Die cast aluminumchromed Piston rings High silicon content aiuminum 2 iron rings Crankshaft Forged steel Bearings Ball bearing front rear Conrod Forged steel Bearings Needle bearings both ends Dimensions Orientation dimensions looking forward along crankshaft upright engine Prop refers propeller back side 1 Firewall prop mount supplied 7-1/8 2 Prop reermost point excluding rear shaft 7 rear housing 3 Prop forwardmost point /4 plug 4 Maximum extension thrust line 4-1/8 top cylinder @ 3-3/4 behind prop 5 Vertical dimensions thrust line a Up 4-1/8 top cylinder 0 3-3/4 behind prop b Down 2-3/16 throttle belicrank bracket @ 4-1/16 behind prop 6 Horizontal extension thrust line 3-38 carb 0 2 behind prop 7 Propeller hub diameter 1-3/8 Bolt hole diameter NA 8 Propeller washer 1-1/32 dia aluminum 9 Mounting bolt pattern 2-7/8 sq shaft center Subjective items following beyond ability measure di rectly offered opinions what worth 1 Overall appearance High quality beautiful workmanship unusual layout 2 Amount quality instructions Adequate clearly written 3 Ease starting a Cold Super excellent 5 6 flips b Hot delightfirst flip usually 4 Ease mounting control hook-up Simple radial mount straightforward hook-up 5 Ease carburetor adjustments Awkward engine running 6 Vibration levels Super smooth - 7 Cowlabillty Plug carb positions can give trouble in4lnetype cowls 8 Crankshaft bearIng slop None subject beyond scope series does seem appropriate point out some simple adjustments necessary proper opera tion spark ignition engine Stated simply possible compressed charge gasoline air cylinder ignited spark jumping between electrodes spark plug spark produced high voltage generated magneto coil timed either mechanical points electronic circuit energy required produced magnets flywheel passing close pole pieces magneto exception electronic ignition circuit things involve gaps proper adjustment various gaps vital operation engine will note data sheets have published include settings An essential tool Big Banger user set ignition feeler gauges avallable auto parts store Lets take look different gaps starting spark plug plug gap affects amount spark produced small extent exact timing will occur gap usually supposed order 0025 0035 points opened closed cam crankshaft points open high tension produced causes spark spark plug Points adjusted positioning crankshaft until points open varying size opening setting can have great effect engine operation Continued page 111 ZDTFTTZTUZGZ2GZZZZ Prop 20121224122422-8 22-10 22-10 22-12 22-14 24-6 24-8 248 24-12 24-14 2416En inc 20-1022-8 [v32][b-1-10-1-10]] 20-B20-1020-10 1600 15001400 1500 IdIRPM 0 2300 IdieRPM 4600 4000 3500 3800 Top RPM tu 5100T RPM P 95875 775 Lb Thrust ~ 335 295 Lb Thrust RPM 00 5000 5050 5250 Top RPM hrust 3513514 e RPMZ 2100 1900 2000 2000 1800 2000 2100 1900 1900 1800 180020001800 72006600 54006500590070007200600061005400560062005800 ~TopR 201918520162020520201617520185ibThrust 18001800190018001900190017001800170017001600 16001700170017001700170014RPM 760071507150720063507400765068007150640064005400530069505800630053504800Top RPM 6265 262727j28 29 27245 rustU st 1981 29 K-21A ENGINE DATA ilent 128 cu iii 21cc CoPrice $16995 Availability Direct & dealers 8249 MIg Klorltz Japan werWeight 4 lb 6 oz mci mount TA SUMMARY ant 1025 lb rpm Kolbo 20-5 prop 201 062 oz/mln fuel consumption supplied Engine mount Yes ne ug d Bob Kirby think probably smoothestrunning engine have tested far Anything RiC W3029 Hoffman Spokane WA 99205 W L Langford 510 Girard Ave Dothan AL 36303 G & G Electronics 497 Central Ave See konk MA 02771 Fred Morgan Box 8516 Cave Creek Stage 28238 N 44th St Phoenix AZ 85020 Ace Service Center Box 511 203 W 19th Higginsville MO 64037 Dundas Hobby Supply 16 Sleepy Hollow Dundas Ont Canada L9H 1H3 Donald J Wadella Dons Radio Control Systems 11392 74th Ave Delta BC Can ada V4C lEl R K Specialties 406 Prospect Dr SW Medicine Hat Alberta Canada TiA 4C1 Mastercraft 4 Linden Rd Chiselhurst Ext East London 5201 South Africa Keep letters flowing dont ask find parts please George M Myers 70 Froehlich Farm Rd Hicksville NY 11801 Big Bangers/Beckman Continued page 29 points never open never close will never spark engine will never run points can set engine runs well should example points too close will stay closed longer should effectively retarding spark engine will lose power especially high speed Points usually set about 0015 fully open magneto air gap should small possible since closer magnets pole pieces go energy will developed spark quality crank shaft bearings size flywheel determine gap needed ensure magnets actually touch go 0010 typical gap chainsaw engines Since gaps mechanical wear vibration can change over period time Periodic adjustment required keep engine running peak performance addition its good idea check things new engine becasue never know what may have happened engine between time left factory time got Listed below additional notes subjective data current set test engines Mag-Aero beautiful engine both fas cinating frustrating Like its big brother Kioritz 24 cu engine extremely well made delight operate first glance seems ideally suited aircraft use turns out have some detracting characteristics large cup-shaped rear housing contains flywheel magneto points As result front engine must less cluttered Big Bangers should make easier cowl Unfortunately position spark plug dictates very flat-faced cowl horizontal protrusion carburetor compli cates mounting in-line cowls Radial cowls would easier extra length engine would require false firewall scale position forward actual firewall engine mounted Despite awkward-seeming layout engine its quality makes outstanding big bird powerplant would particularly useful some Quarter Scale designs originally powered big glow engines Continued page 114 August1981 111 I-NDIAN CITY RADiO CONTROL CLUB mSENTS GREATER MICHIGAN MODELERS SHOW & EXPO ill iS WOATS CAR$ MANLtFACT*J#EES STATIC DI$PLAYSSWAP SHOP 23A 1981 Wt4Rht MI Aftillery Anuaory1 Oak Park MichiR F7 RICKS R/C MODELS IN 81 ITS INTRODUCING THE RICK STICK SUPREMETHE WEEKENDER FLITE BOX SPORTTRAINER- FULLYAEROBATIC SIZE 12% x 12% x 18 IPLYWOOD SANDED READY FOR PRIMER 4 CliCABINET INCLUDED Pro-BuiltSEALER HARDWARE AND 16 DRAWER $8995 Engine 25 40 $4995 Pro-Cut Kit Hardware Landing Gear Full Length Wood md Pre-Built Ready Fine Sand & Cover Full Length Balsa Wood & Spruce Spars Hinged Surfaces Hardware HalIco Gear Nylon Bolts Tapped Bolt Gear & Wing SPACE FOR 15 Drawer Cabinet 1-Gal Fuel Battery Fuel Pump Power Panel Prop Bin Tool Tray Electric Starter Cleaner Towels No Other Like Od. PS Odac NG aede SN lower vibration level Mag-Aero would compatible lighter construction has proven inadequate larger chainsaw engines example Mag-Aero would ideal Piper Cub 12- 14-lb range Another interesting possibility radial engine version Gee Bee Sportster impressed quality easy start ing smooth running engine Roper 19 engine about least ex pensive gasoline burner available Homer Sales offers used factory demo engines $3495 new engines $4995 couple things should clarified however factory referred Roper factory engines new used have modified aircraft use modification difficult can done use machine tools operation outlined instruction sheet comes engine addition doing engine mods will need make buy motor mount prop hub Homer offers both prop hubs made Quadra will fit test engine used demo units Gene Homer already done conversion work Under circumstances skipped usual break-in run went right test runs found backing idle screw out way resulted idle speeds no lower 3000 rpm Since stop arm resting directly screw bracket nothing could field High speed operation affected continued tests discussing engine Gene Homer mentioned could bear start fact instructions recommends using pulley cord possible reason hard starting fairly large magneto air gap required because rather loose needle bear ings crankshaft Once started engine produced credible power its size surprisingly comfort able high speeds low speeds however shaker engine useable reasonable value price Husky 23 several years J C Enterprises has selling converted 2 cu McCulloch chainsaw engine called Husky test engine first new slightly larger version putting market 23 almost identical earlier model except size layout Husky best have seen aircraft application Both carburetor magneto mounted front cylinder instead sticking out side bottom engine makes cowling engine much easier built-in vacuumoperated pump oiling saws chain left engine converted could used smoke system remove pump drill new mounting hole can cut another inch off bottom casting get engine tighter cowls unfortunate difference new engine carb does have built-in choke other hand has larger cooling fins should run little cooler over long periods full throttle feel Husky 23 valuable addition Big Banger list will particu larly useful models in-line cowls Kawasaki TA-5 1 reported smaller Kawasaki engine Part series About can say about same quality beautiful workmanship superb operating characteristics noted earlier report change carburetor mounting resulted much easier adjustment running engine change quite easy work minor surprise fact carb has no idle adjustment screw caused us little difficulty during tests would no problem normal installation use throttle servo set idle Another minor difference between two engines involves rectangular crankcase cast ing removing excess material has little effect weight engines no real effect size smaller model can effect TA-5 1 relocating electronic ignition module trimming casting down magneto about inch can removed could important some cowls its smooth running power output adjustment-free electronic ignition consider Kawasaki outstanding engine Kiorits 48 have complete report engine time felt should make some comments about engine several available Roush Mfg special order basis both larger expensive average modeler will ever want special purpose power plants would out place average flying field other hand have special application facilities handle its nice know power available lot good things about engine pointed out above Husky laid out nicely application engine better carb right smack front cylinder entire ignition system inside flywheel exhaust comes out back course weve learned cope its really nice see engine no 114 Model Aviation Send SASE Free Brochure 0 Oealer Inquiries Invited S Florida Residents Add 4% Sales Tax CHECK OR MO KS R/t MODELS INC Handling ft shiomog 1730 DREW ST CLEARWATER FL 33515 FIightIine shirts have got covered One-liner Shirts sioso Plane Shirts 5725 top quality football shirts complete history back sky blue blue printing war- ground colorful \W/ll birds red printing Pitts airplanes applied sky blue shirts design fine line followed aarowstr aoearoP-3a UgiWilog-korkane FlU-i ConalP-39 NacobraLyandor AF4F WildcatP40 WahawkSpitfiw F6F I-lelicatP47 ThondebosTyphoon profile view classic airplane F7F TigewatP-Si PAatanga 17 Aylng Fote FBF BearcatPM Black Widow5-24 LIberator crie ui riurrIur d luL people Sky blue T-shirts printed two colors Pitts shirt white printed red black ~auIiSfl1uaee Mens sizes Sm 132-361 Med 38-40J Lg 142441 XL 1461 OdPP NameSend check money order Iplus SI P/HI AddressFlIghtilne Shirts EtcAdd 65% taX california 12504 Saratoga AvenueSend SASS CityStateZipSaratoga CA 95070 bWdOe SizeStyleDesignTotal SIAiiow 4-6 weeks delivelyl Machine-shaped balsa plywood hardwood Die-cut ribs constant chord wing Dursi main landing gear tricycle gear Hardware package nuts bolts control RAPIER s nose-gear bearing Fuel tank size 10 oz 12 oz Flying weight 6 lb Wingspan 57 Wing area 752 sq Wing chord 13 SPECIFICATIONSFuselage 48 Build 15 hours gentle tlyer wIth a40 great sport tlyer a60 Semi-symmetrical wing long moment big plane responsive tlyer tully aerobatic Four-channel radio engine elevator rudder Complete building instruction booklet Basic materials balsa plywood2657 N 6 188th Street selected hardwoodsMam Ftoda 33180 TelepSone 935-1436 wider flywheel would great would just engine size Quadra 24 Kioritz engine comes larger Kioritz professional chainsaws Roush brothers have done beautiful job converting aircraft use understand inquiries about other large engines coming people building micro-lights powered hang gliders Roush can supply engines up 5 6 dil reason have little operational data engine difficulty getting run engine has fairly high compression starting procedure somewhat different what have using first session engine resulted run mainly because werent doing things right next weekend little luck getting started first time ran some ignition problems decided hold off until could get ourselves sorted out reporting what can now will add operating data get interested using engine selves impressed Like Kioritz products very high quality conversion work match consider start ing problems due own lack familiarity level engine size wish thank following firms assistance part Big Banger project GB Associates Inc 21658 Cloud Way Hay ward CA 94545 Kawasaki Dynathrust Props Inc 2541 NE 11th Ct, Pompano Beach FL 33062 Giezendanner USA P0 Box 818 Pottatown PA 19464 Grish Bros St John IN 46373 Homer Sales Inc 300 Dixie Hwy Beecher IL 60401 Roper JC Enterprises 2251 SW 28th Terrace Ft Lauderdale FL 33312 Husky Mag-Aero Mfg Co P0 Box 490 Freeland WA 98249 Roush Mfg P0 Box 251 Sandyville OH 44671 Kioritz Top Flite Models Inc 1901 Narragansett Ave Chicago IL 60639 J & Z Products 25029 S Vermont Ave Harbor City CA 90710 Zinger SAFE FLYING IS NO ACCIDENT Scaling Palumbo Continued page 33 force centrifugal force Centrifugal force will exist model moving along straight flight path magnitude centrifugal force equal weightW times velocity V squared divided radius R maneuver times earths gravitational acceleration g32 ft/sec/sec math ematical formula maneuver force therefore WV2 M gR Equation 1 ratio M W simply V2/gR use lower-case letters denote models velocity maneuver radius ratio v2/gr model Equating full-size airplanes ratio models ratio MIW m/w obtain V2_ v2 R r Equation 2 because g common both Now lets assume models scale factor number denoted N model manuever within scale airspace must maneuver within scale its dimensions Hence maneuver radius model should scaled accordance models scale factor mathematically means r Substituting R Equation 2 gives V Equation 3 establishes relationship between models speed speed full-size airplane necessary ensure model will perform within scale airspace Note since distance has scaled directly N velocity distance divided time can now seen full-size airplanes time frame stretched square root N compared models time frame As example full-size airplane performing 600-ft diameter loop average speed 150 mph would scale 1/6-size model performing 100-ft diameter loop average speed 61 mph would take 86 seconds full-size airplane complete loop 35 seconds model complete itslp formula Eq 3 presented graphically Fig 2 variety scale factors mathematically inclined aerodynamic forces airplane lift drag direct proportion air density wing area square velocity proportionality constant called force coefficient Mathematically CA$V2S August1981 115 h-L1~at is
Edition: Model Aviation - 1981/08
Page Numbers: 28, 29, 111, 114, 115
Beckman Kirby Crawford hi ban ersfo Part Three series power plants big uns Bob Kirby discuss five engines range smallest about biggest gasoline-burners THIS INSTALLMENT covers almost entire size range Big Bird gasoline burners 12 Cu fl MagAerotoa48 Cu special order engine Roush Mfg interesting note both engines based Kioritz products between extremes look three engines Roper Husky Kawasaki Refer Part 1 series April 81 Model Aviation description test equipment procedures has significant addition test equipment beginning have doubts about venerable old Heathkit Thumb Tach Now thanks Dick Penrod Giezen danner USA have use Giezendanner Digital Tachometers device easier read much accurate addition helped us identify rather embarrassing error original setup Bobs old Thumb Tach used several years instruction book long gone checked agalnst incandescent light 3000 rpm reading seemed correctdue faulty memory little thought would have realized should have 3600 until read instructions Digital Tach mistake became obvious cross-checking between two find multiplying Thumb Tach readings 12 yields same reading Giezendanner unit within rpm accuracy Thumb Tach itself previously published rpm D TZTZZDTZDTZ TZ KTZD T 15-61164 165 166 16-6 16-8 186 18-6 186 18-8 18-8 18-8 18-10 18-10 20-5 204 20-6 20-8 20-8 RPM 1900 1900 1900 1800 1800 f7 i T T7 1700 1700 1600 1600 1600 1600 1400 1800 1800 mu Top RPM 7350 18400 73006900 6850 6300 5600 6200 5800 5600 5600 5800 4950 5300 5500 5000 5600 5200 4600 Lb Thrust 65775 75 8825 8 55 10 5 10 9510 le RPM See Rorer Ntes Top RPMIOOOU G1009600940087007150840076007400710072006000650070006200700063506550 rust 145 135 16155 155 1614175 16145 16151415155 155 165 155 15 RPM 2500 2600 2500 2500 2600 2500 2400 2200 2500 2300 2600 2300 2100 EEL RPM 00 8500 3000 8000 8400 7400 8400 7300 7200 hrust18 205 201719195 185 185 202020195 2 RPMDDynathrustGGrish 2200 2200 23002000 2000 Top RPMKKoIboTTop FlitsZZinger8250 8900 8100 8550 7800 7500 rust-2353525562 28 Model Aviation smaii DUT impressive Mag-Aero Hywneel maaneto onints arm innida thin mar hounino Digital Tachometerfrum iaIeunuanner UM vaiuaoieaooiion tfl projects gear Headout units 100 rpm point prop move around until steady reading obtained ins HOPC 19 purrsawayon tuel consumption test run lumberyard props front Data charts continued next page figures should adjusted Please accept apologies inconvenience Note thrust figures affected valid published accuracy digital readout Giezen danner tach make possible get closer rpm readings tach reads hundreds stable enough allow interpolation mid point between readings example steady reading 54 means 5400 rpm reading changing back forth between 54 55 can read 5450 rpm tach easy enough use simply turn point toward propeller vary position until steady reading obtained best position will depend light conditions pleased tachs operation feel valuable addition project mail talking other modelers seems lot people trying use engines understand basics spark ignition Thats understandable since several generations modelers have never used anything glow engines models complete discussion Prop hub YesMuffler Noexhaust stack supplied Other 90-dog throttle linkage Additional items requird excluding prop fuel tank None Recommended propeller 18-6 Recommended fuei mix 201 Carburetor Make type Waibrodiaphram pump Controls availabie Throttle Adjustments avali idle set screw high low speed mixture ignitionType Magneto mechanical points Spark plug Champion RCJ8 Recommended gap specified Magneto gap specified Point gap specified Kill disable system Magneto grounding wire Internal details induction Direct piston porting Cyiinder Die cast aluminumchromed Piston rings High silicon content aiuminum 2 iron rings Crankshaft Forged steel Bearings Ball bearing front rear Conrod Forged steel Bearings Needle bearings both ends Dimensions Orientation dimensions looking forward along crankshaft upright engine Prop refers propeller back side 1 Firewall prop mount supplied 7-1/8 2 Prop reermost point excluding rear shaft 7 rear housing 3 Prop forwardmost point /4 plug 4 Maximum extension thrust line 4-1/8 top cylinder @ 3-3/4 behind prop 5 Vertical dimensions thrust line a Up 4-1/8 top cylinder 0 3-3/4 behind prop b Down 2-3/16 throttle belicrank bracket @ 4-1/16 behind prop 6 Horizontal extension thrust line 3-38 carb 0 2 behind prop 7 Propeller hub diameter 1-3/8 Bolt hole diameter NA 8 Propeller washer 1-1/32 dia aluminum 9 Mounting bolt pattern 2-7/8 sq shaft center Subjective items following beyond ability measure di rectly offered opinions what worth 1 Overall appearance High quality beautiful workmanship unusual layout 2 Amount quality instructions Adequate clearly written 3 Ease starting a Cold Super excellent 5 6 flips b Hot delightfirst flip usually 4 Ease mounting control hook-up Simple radial mount straightforward hook-up 5 Ease carburetor adjustments Awkward engine running 6 Vibration levels Super smooth - 7 Cowlabillty Plug carb positions can give trouble in4lnetype cowls 8 Crankshaft bearIng slop None subject beyond scope series does seem appropriate point out some simple adjustments necessary proper opera tion spark ignition engine Stated simply possible compressed charge gasoline air cylinder ignited spark jumping between electrodes spark plug spark produced high voltage generated magneto coil timed either mechanical points electronic circuit energy required produced magnets flywheel passing close pole pieces magneto exception electronic ignition circuit things involve gaps proper adjustment various gaps vital operation engine will note data sheets have published include settings An essential tool Big Banger user set ignition feeler gauges avallable auto parts store Lets take look different gaps starting spark plug plug gap affects amount spark produced small extent exact timing will occur gap usually supposed order 0025 0035 points opened closed cam crankshaft points open high tension produced causes spark spark plug Points adjusted positioning crankshaft until points open varying size opening setting can have great effect engine operation Continued page 111 ZDTFTTZTUZGZ2GZZZZ Prop 20121224122422-8 22-10 22-10 22-12 22-14 24-6 24-8 248 24-12 24-14 2416En inc 20-1022-8 [v32][b-1-10-1-10]] 20-B20-1020-10 1600 15001400 1500 IdIRPM 0 2300 IdieRPM 4600 4000 3500 3800 Top RPM tu 5100T RPM P 95875 775 Lb Thrust ~ 335 295 Lb Thrust RPM 00 5000 5050 5250 Top RPM hrust 3513514 e RPMZ 2100 1900 2000 2000 1800 2000 2100 1900 1900 1800 180020001800 72006600 54006500590070007200600061005400560062005800 ~TopR 201918520162020520201617520185ibThrust 18001800190018001900190017001800170017001600 16001700170017001700170014RPM 760071507150720063507400765068007150640064005400530069505800630053504800Top RPM 6265 262727j28 29 27245 rustU st 1981 29 K-21A ENGINE DATA ilent 128 cu iii 21cc CoPrice $16995 Availability Direct & dealers 8249 MIg Klorltz Japan werWeight 4 lb 6 oz mci mount TA SUMMARY ant 1025 lb rpm Kolbo 20-5 prop 201 062 oz/mln fuel consumption supplied Engine mount Yes ne ug d Bob Kirby think probably smoothestrunning engine have tested far Anything RiC W3029 Hoffman Spokane WA 99205 W L Langford 510 Girard Ave Dothan AL 36303 G & G Electronics 497 Central Ave See konk MA 02771 Fred Morgan Box 8516 Cave Creek Stage 28238 N 44th St Phoenix AZ 85020 Ace Service Center Box 511 203 W 19th Higginsville MO 64037 Dundas Hobby Supply 16 Sleepy Hollow Dundas Ont Canada L9H 1H3 Donald J Wadella Dons Radio Control Systems 11392 74th Ave Delta BC Can ada V4C lEl R K Specialties 406 Prospect Dr SW Medicine Hat Alberta Canada TiA 4C1 Mastercraft 4 Linden Rd Chiselhurst Ext East London 5201 South Africa Keep letters flowing dont ask find parts please George M Myers 70 Froehlich Farm Rd Hicksville NY 11801 Big Bangers/Beckman Continued page 29 points never open never close will never spark engine will never run points can set engine runs well should example points too close will stay closed longer should effectively retarding spark engine will lose power especially high speed Points usually set about 0015 fully open magneto air gap should small possible since closer magnets pole pieces go energy will developed spark quality crank shaft bearings size flywheel determine gap needed ensure magnets actually touch go 0010 typical gap chainsaw engines Since gaps mechanical wear vibration can change over period time Periodic adjustment required keep engine running peak performance addition its good idea check things new engine becasue never know what may have happened engine between time left factory time got Listed below additional notes subjective data current set test engines Mag-Aero beautiful engine both fas cinating frustrating Like its big brother Kioritz 24 cu engine extremely well made delight operate first glance seems ideally suited aircraft use turns out have some detracting characteristics large cup-shaped rear housing contains flywheel magneto points As result front engine must less cluttered Big Bangers should make easier cowl Unfortunately position spark plug dictates very flat-faced cowl horizontal protrusion carburetor compli cates mounting in-line cowls Radial cowls would easier extra length engine would require false firewall scale position forward actual firewall engine mounted Despite awkward-seeming layout engine its quality makes outstanding big bird powerplant would particularly useful some Quarter Scale designs originally powered big glow engines Continued page 114 August1981 111 I-NDIAN CITY RADiO CONTROL CLUB mSENTS GREATER MICHIGAN MODELERS SHOW & EXPO ill iS WOATS CAR$ MANLtFACT*J#EES STATIC DI$PLAYSSWAP SHOP 23A 1981 Wt4Rht MI Aftillery Anuaory1 Oak Park MichiR F7 RICKS R/C MODELS IN 81 ITS INTRODUCING THE RICK STICK SUPREMETHE WEEKENDER FLITE BOX SPORTTRAINER- FULLYAEROBATIC SIZE 12% x 12% x 18 IPLYWOOD SANDED READY FOR PRIMER 4 CliCABINET INCLUDED Pro-BuiltSEALER HARDWARE AND 16 DRAWER $8995 Engine 25 40 $4995 Pro-Cut Kit Hardware Landing Gear Full Length Wood md Pre-Built Ready Fine Sand & Cover Full Length Balsa Wood & Spruce Spars Hinged Surfaces Hardware HalIco Gear Nylon Bolts Tapped Bolt Gear & Wing SPACE FOR 15 Drawer Cabinet 1-Gal Fuel Battery Fuel Pump Power Panel Prop Bin Tool Tray Electric Starter Cleaner Towels No Other Like Od. PS Odac NG aede SN lower vibration level Mag-Aero would compatible lighter construction has proven inadequate larger chainsaw engines example Mag-Aero would ideal Piper Cub 12- 14-lb range Another interesting possibility radial engine version Gee Bee Sportster impressed quality easy start ing smooth running engine Roper 19 engine about least ex pensive gasoline burner available Homer Sales offers used factory demo engines $3495 new engines $4995 couple things should clarified however factory referred Roper factory engines new used have modified aircraft use modification difficult can done use machine tools operation outlined instruction sheet comes engine addition doing engine mods will need make buy motor mount prop hub Homer offers both prop hubs made Quadra will fit test engine used demo units Gene Homer already done conversion work Under circumstances skipped usual break-in run went right test runs found backing idle screw out way resulted idle speeds no lower 3000 rpm Since stop arm resting directly screw bracket nothing could field High speed operation affected continued tests discussing engine Gene Homer mentioned could bear start fact instructions recommends using pulley cord possible reason hard starting fairly large magneto air gap required because rather loose needle bear ings crankshaft Once started engine produced credible power its size surprisingly comfort able high speeds low speeds however shaker engine useable reasonable value price Husky 23 several years J C Enterprises has selling converted 2 cu McCulloch chainsaw engine called Husky test engine first new slightly larger version putting market 23 almost identical earlier model except size layout Husky best have seen aircraft application Both carburetor magneto mounted front cylinder instead sticking out side bottom engine makes cowling engine much easier built-in vacuumoperated pump oiling saws chain left engine converted could used smoke system remove pump drill new mounting hole can cut another inch off bottom casting get engine tighter cowls unfortunate difference new engine carb does have built-in choke other hand has larger cooling fins should run little cooler over long periods full throttle feel Husky 23 valuable addition Big Banger list will particu larly useful models in-line cowls Kawasaki TA-5 1 reported smaller Kawasaki engine Part series About can say about same quality beautiful workmanship superb operating characteristics noted earlier report change carburetor mounting resulted much easier adjustment running engine change quite easy work minor surprise fact carb has no idle adjustment screw caused us little difficulty during tests would no problem normal installation use throttle servo set idle Another minor difference between two engines involves rectangular crankcase cast ing removing excess material has little effect weight engines no real effect size smaller model can effect TA-5 1 relocating electronic ignition module trimming casting down magneto about inch can removed could important some cowls its smooth running power output adjustment-free electronic ignition consider Kawasaki outstanding engine Kiorits 48 have complete report engine time felt should make some comments about engine several available Roush Mfg special order basis both larger expensive average modeler will ever want special purpose power plants would out place average flying field other hand have special application facilities handle its nice know power available lot good things about engine pointed out above Husky laid out nicely application engine better carb right smack front cylinder entire ignition system inside flywheel exhaust comes out back course weve learned cope its really nice see engine no 114 Model Aviation Send SASE Free Brochure 0 Oealer Inquiries Invited S Florida Residents Add 4% Sales Tax CHECK OR MO KS R/t MODELS INC Handling ft shiomog 1730 DREW ST CLEARWATER FL 33515 FIightIine shirts have got covered One-liner Shirts sioso Plane Shirts 5725 top quality football shirts complete history back sky blue blue printing war- ground colorful \W/ll birds red printing Pitts airplanes applied sky blue shirts design fine line followed aarowstr aoearoP-3a UgiWilog-korkane FlU-i ConalP-39 NacobraLyandor AF4F WildcatP40 WahawkSpitfiw F6F I-lelicatP47 ThondebosTyphoon profile view classic airplane F7F TigewatP-Si PAatanga 17 Aylng Fote FBF BearcatPM Black Widow5-24 LIberator crie ui riurrIur d luL people Sky blue T-shirts printed two colors Pitts shirt white printed red black ~auIiSfl1uaee Mens sizes Sm 132-361 Med 38-40J Lg 142441 XL 1461 OdPP NameSend check money order Iplus SI P/HI AddressFlIghtilne Shirts EtcAdd 65% taX california 12504 Saratoga AvenueSend SASS CityStateZipSaratoga CA 95070 bWdOe SizeStyleDesignTotal SIAiiow 4-6 weeks delivelyl Machine-shaped balsa plywood hardwood Die-cut ribs constant chord wing Dursi main landing gear tricycle gear Hardware package nuts bolts control RAPIER s nose-gear bearing Fuel tank size 10 oz 12 oz Flying weight 6 lb Wingspan 57 Wing area 752 sq Wing chord 13 SPECIFICATIONSFuselage 48 Build 15 hours gentle tlyer wIth a40 great sport tlyer a60 Semi-symmetrical wing long moment big plane responsive tlyer tully aerobatic Four-channel radio engine elevator rudder Complete building instruction booklet Basic materials balsa plywood2657 N 6 188th Street selected hardwoodsMam Ftoda 33180 TelepSone 935-1436 wider flywheel would great would just engine size Quadra 24 Kioritz engine comes larger Kioritz professional chainsaws Roush brothers have done beautiful job converting aircraft use understand inquiries about other large engines coming people building micro-lights powered hang gliders Roush can supply engines up 5 6 dil reason have little operational data engine difficulty getting run engine has fairly high compression starting procedure somewhat different what have using first session engine resulted run mainly because werent doing things right next weekend little luck getting started first time ran some ignition problems decided hold off until could get ourselves sorted out reporting what can now will add operating data get interested using engine selves impressed Like Kioritz products very high quality conversion work match consider start ing problems due own lack familiarity level engine size wish thank following firms assistance part Big Banger project GB Associates Inc 21658 Cloud Way Hay ward CA 94545 Kawasaki Dynathrust Props Inc 2541 NE 11th Ct, Pompano Beach FL 33062 Giezendanner USA P0 Box 818 Pottatown PA 19464 Grish Bros St John IN 46373 Homer Sales Inc 300 Dixie Hwy Beecher IL 60401 Roper JC Enterprises 2251 SW 28th Terrace Ft Lauderdale FL 33312 Husky Mag-Aero Mfg Co P0 Box 490 Freeland WA 98249 Roush Mfg P0 Box 251 Sandyville OH 44671 Kioritz Top Flite Models Inc 1901 Narragansett Ave Chicago IL 60639 J & Z Products 25029 S Vermont Ave Harbor City CA 90710 Zinger SAFE FLYING IS NO ACCIDENT Scaling Palumbo Continued page 33 force centrifugal force Centrifugal force will exist model moving along straight flight path magnitude centrifugal force equal weightW times velocity V squared divided radius R maneuver times earths gravitational acceleration g32 ft/sec/sec math ematical formula maneuver force therefore WV2 M gR Equation 1 ratio M W simply V2/gR use lower-case letters denote models velocity maneuver radius ratio v2/gr model Equating full-size airplanes ratio models ratio MIW m/w obtain V2_ v2 R r Equation 2 because g common both Now lets assume models scale factor number denoted N model manuever within scale airspace must maneuver within scale its dimensions Hence maneuver radius model should scaled accordance models scale factor mathematically means r Substituting R Equation 2 gives V Equation 3 establishes relationship between models speed speed full-size airplane necessary ensure model will perform within scale airspace Note since distance has scaled directly N velocity distance divided time can now seen full-size airplanes time frame stretched square root N compared models time frame As example full-size airplane performing 600-ft diameter loop average speed 150 mph would scale 1/6-size model performing 100-ft diameter loop average speed 61 mph would take 86 seconds full-size airplane complete loop 35 seconds model complete itslp formula Eq 3 presented graphically Fig 2 variety scale factors mathematically inclined aerodynamic forces airplane lift drag direct proportion air density wing area square velocity proportionality constant called force coefficient Mathematically CA$V2S August1981 115 h-L1~at is