Radio Control Pylon Racing Bill Hager ACTIVITY have just received letter Darwin Barrie Scottsdale Ari zona has area past several years has much rac ing looks though now changing As February 22-23 1986 will Formula race Darwin CD Biesemeyer Tool Co Phoenix Pylon Racing Association Arizona Model Aviators sponsors will waiting results guys seems though increasing amount -Scale Pylon Racing Northeast find quite few people raced living Ohio now racing Quarter Scale 85 started using four-stroke engines might add much success QSPRA newsletter comes following four-stroke engines FOUR-STROKING IT lot information being published about four-strokes Well try clarify technical points such power torque horsepower rpm thrust etc None have changed meaning compared two-strokesits just way developed four-stroke thats different horsepow er 16 17000 rpm somehow still 16 hp now being developed 11000 rpm thing changes Typical HP Torque Curves 0 16 HP 7, 12in360 45 N -\ 12/7 V j H AII 5000 10000 15000 20000 25000 RPM get 16 horsepower out big tour-stroke engines smaller twostroke ones However its rpm get HP impor tant consideration four-stroker peaks about 12000 rpm two-strokes need 18000 22000 rpm Hardwood beams Floor fuel compartment ap balsa gussets front Cutout inbeams beveled clear glass fuselagefuse curvature glued fuse nose ring Original firewall cutout width beam mounts depth crank centerline Notched hardwood beams Heres group fliers modifies Great Planes Cosmic Wind quarter-scale kit use big 12 cu four-stroke engines now use racing Fuel tank location wedge foam Carburetor location Original firewall supports back beam mounts generally will front carburetor pictureand adds confusion what being done HP want thrust low-pitch prop will give you must keep prop diameter large load 5700 Typical 12 4-Stroke Curves 4Q0010000 12000 T T / / / 5000 Cheek cowl outline .OS Saito will require draincowl cutouts clear frontmount rocker boxes engine down absorb HP har ness workthe thrust pull airplane low-pitch prop will give lower airspeed fine light slowflying aircraft such Piper Cub shouldnt fly fast anyway Because slow sport flying applica HOTtion four-stroke started 120not hear propeller pitches over six inch es manufacturers literature N see things such 15 x 8 indurd o HP 16 x 6 etc Increasing propeller diameter loads engine same inch change pitch com bination isnt enough engine easily overrevs loses power see explanation further may damage both itself pocketbook overrev results valve float exactly what sounds like high enough rpm inertia springiness Some four-strokes hotter others peak HP occurs higher rpm However overall torque curve may well lower means wont lug large prop normal 10000 RPM UL RPM RON GE St 1 15000 Continued page 139 56 Model Aviation RC Old-Timers/Mathews Continued page 53 non-SAM-era models Hal deBolt tells will soon start column early RC designs Model Airplane News Id like some material Free Flight same approximate time frame am particularly turned PAA-Load both large small designs wartime goodies such Kid etc some really attractive sport-types such Pacificoaster last column Any photos would greatly appreciated Naturally puts would helpful well Two examples sort thing thinking Veco Sioux Bill Winters Midwest Sniffer enlargements published Flying Models few years back could get excited about sort conceptor impor tant youve tried itwould please drop line Dee B Mathews 8420 Nantucket Wichita KS 67212 RC Giant Scale/Beckman Continued page 55 Conclusion least conclusion Twins multi-engined models dont have considered terrible course theyre going compli cated turns out fail its pretty much same reasons models fall moral story learn failures apply lessons new project Pretty soon failures get few far between Bob Beckman 8248 Holly Grove Ct Manassas VA 22110 RC Pylon Racing/Hager Continued page 56 valve train reaches point valves dont follow bump cam may hit piston 14 x 10 prop its resulting rpm combination will keep well away since engines will run mid 8OOOs ground 10000 air diving three approved engines have redlines well past 12000 rpm Since racing need speed get pitch has increase because four-stroke engines now roughly 10000 rpm saw 15000 two-stroke 60 air Assuming 100 mph before seven-in pitch 15000 rpm now need 10 inches pitch 10000 rpm same speed 7 x 15000 approximately equals 10 x 10000 An added bonus larger prop efficient smaller thrust consistent rpm doesnt fall off turn since four-stroke lugs better meaning doesnt slow down much same ap plies takeoff climbing giving forgiving flight envelope can begin realize what have heard before propeller matching plane engine very important Back power torque Horsepower always combination torque rpm HP UE x RPM x k Torque twisting ability engine crankshaft have lugger always occurs lower rpm horsepow er peak 12 bigger engine has torque 60 half its size 12 generates torque much lower rpm Thats 12 11000 rpm 60 17000 rpm can both rated 16 horsepower just develop different set conditions Two-strokes have become powerhouses because easy increase rpm Look characteristics three engines see HP developed 12 cubic inch four-stroke 60 cubic inch two-stroke 45 cubic inch twostroke ducted fan engine deliver ap proximately 16 HP graph front column RH Torque climbs drops off approximately 2A HP max imum HP keeps climbing after torque drops because rpm still climbing torque drops faster rpm climbs HP starts drop hot engine sharper peaks types engines dif ficult set useful certain props Typically l2s use 13/15-inch prop 60s 11-inch 45s 5/9 inches 45s can actually develop HP cant use because dont have torque turn bigger props need larger prop higher-speed engine wont let engine get its horsepower peak doesnt matter horses liter ature says its rated Look curves 12 closely graph front column BH An engine doesnt develop HP automatically smaller prop just lets get up torque curve closer HP peak raised peak hotter engine may have shifted lower torque-curve anyway Horsepower Hop-up As long compare engines using same prop extra horsepower simple sounds since rpm wont go up itself unless changes made engine hop-up. engine de signed differently torque must creased some other way since rpm must go up takes torque easiest way power let rev. smaller prop less pitchbut allowed fore back torque increase THE LEADER IN COM PETITION NEW i 4 CYCLE THP DESIGN PRICE f 299 379 14479 15689 16989 NEW F 4 j NEW HIGH TECH AIRFOIL SECTION lOTO 20% INCREASE IN THRUST MFG OF SELECT HARD MAPLE WOOD WILL NOT FATIGUE LIKE SYNTHETICS FUEL PROOF HIGH LUSTER FINISH DIAPITCHPRICE 534149 634149 72833456179 833/,4568189 845667199 9456677199 104S667209 106W8W209 106EW219 ii46777/,7I,8229 115W229 11SEW239 1167239 124W279 125W279 1256279 1356349 1456459 1556659 164VzN989 16678969 PROPELLERS April1986 139 TAILORED HELICAL PITCH DEVELOPED TO GIVE MAXIMUM THRUST AT 4 CYCLE ENGINE RPM ALL THE LATEST TECHNIQUES USED ON OUR PRO SERIES 3 SEE BELOW PITCH THP 86 77 8 877 8 677 8 67 678 PRO SERIES 3 RC PYLON RACING SERIES 500 DIA PITCH PRICE 7SN 5/N279 8I 6/,7/z78 299 SERIES 400C 8 66777 289 9777/289 W WIDE BLADE EW EXTRA WIDE N NARROW 9 New Br SnehslDeimar Lightest weight hand start ready-to-mount englnesu th market 31 *27500 34 $34500 37- *35500 42 $37500 Engines Complete Nothing Extra Buy Choice points 31or CDI ignition %34-553 2a-SJEP&7-55s4a-65 NP42-553 Ioz. TSP Features Customized newest German engines parts lai t ting Salle aura Tap smoka Caritwelci Unkaga Ignition CH Elactronicala 48 V Ignition Pack ty Switch lt Hub etor Spk PIgs Waranty ca Faulty Parts Workmanship T G Mtg 857 HIgh Mountain Rd North Haldon NJ 07508 e 201 427-3845 HP a Bigger Engine. verb otcn. no way b Increase Compression old hot rod trick. allowed c More Breathing air fuel. bigger ... allowed may work engine cant draw fuel anyway d Better breathing larger valves passages etc.. allowed may actually hurt carb cain im proved well e The old hot cam. allowed very difficult anyway Changing cam timing may make things worse lower rpm other tricks like bigger carb Hot cams almost always used get breathing high rpm increases horsepower although peak torque may actually less before Hop-up isnt simple engine load ing such prop controlled brings up subject newer hotter engines make noticeably horsepower load rpm must come 1 Bigger carbs 2 Higher-rpm tuning design 3 Different-than-glow ignition 4 Hotter cams better breathing higher rpm 5 Supercharging tuned intake exhausts also type supercharging Youll notice increased compres sion old hot rod trick hasnt mentioned because glow ignition ralsing compression current engines will get trouble detona tion will slow down dont lose prop Higher-horsepower engine models introduced will somewhat dif ferent set up higher rpm special take ignition systems Extra horse power will mean complication expense manufacturers will keep bread-and-butter models available Because competition engines will stay very similar other performance information intended make experts out just help understand difference between hearsay buzzwords reality proven technical facts disposal keep engines competitive equiva lent Dont panic advertising high horsepower. talk usable horse power racing conditions care feeding Fours 1 Keep fuel tank close carb centerline possible 2 Read instructions break engine using rich needle valve setting 3 To start three approved engines open full throttle close choke giow off flip engine through two three times until fuel runs out exhaust close throttle open choke turn engine spinner back forth rid excess fuel light glow plug has hot because heavy elements fourstroke plugs turn prop spinner backwards slowly until feel back wards compression snap spinner back compression. engine will usual ly start didnt usually its still stiff storage oil engine must snappy free plug may hot enough Maybe need choke again difficult flood since fuel doesnt go through crankcase excess fuel can run out exhaust pipe side-mounted engines Always rock prop back forth clear excess fuel Fuel will compress can bend rodthis especially true use electric starter use dont choke much clear chamber first rocking spinner will need super battery starter use Several us have use electric starter yet still get one-flip starts follow sequence got one-to-two-flip starts last summer. four-strokers dont load up after idling long time 4 Tighten prop before flying session prop has moved after flight probably too lean engine detonating 5 Follow instructions set valves after first hour running once hour after valve clearance changes much after first hour proba bly running too lean pushing 6 Oil engine through overflow tube after flying once hour adjusting valves under rocker covers making sure runs down pushrod tubes oil cam 7 Use tachometer setting needle especially first time cant hear change much fourstrokes Typically back off 600-700 rpm first hour Enya OS especially least 300 rpm racing Saito appears less sensitive Learn engine/fuel tank combination tach just guidelines engine may bit different much different fuel system may drawing well should DONT TRUST YOUR EAR blow props engines trying tell you didnt set right Send tips ideas can pass readers See next month Bill Hager 706 Glen Haven Dr Conroe TX 77385 RC Helicopters/Jolly Continued page 57 pitch-curve adjustment both high low hovering memory idle-up pitch trim 25% range authority invert switch throttle hold two methods gyro control retract switch course dual rates aileron elevator functions sounds like lotits because 7H1 has just about everything Helicopter jock could want addition its laid out such fashion wont have trouble getting everything copter screaming around sky Airtronics also thoughtful enough add inhibit options invert throttle hold gyro throttle/rudder mix case dont want accidentally use perhaps youd like fly fixed-wing model radio test radio came equipped Air tronics new dual-conversion narrow-band receiver measures 2A x 1 x es 140 Model Aviation I
Edition: Model Aviation - 1986/04
Page Numbers: 56, 139, 140
Radio Control Pylon Racing Bill Hager ACTIVITY have just received letter Darwin Barrie Scottsdale Ari zona has area past several years has much rac ing looks though now changing As February 22-23 1986 will Formula race Darwin CD Biesemeyer Tool Co Phoenix Pylon Racing Association Arizona Model Aviators sponsors will waiting results guys seems though increasing amount -Scale Pylon Racing Northeast find quite few people raced living Ohio now racing Quarter Scale 85 started using four-stroke engines might add much success QSPRA newsletter comes following four-stroke engines FOUR-STROKING IT lot information being published about four-strokes Well try clarify technical points such power torque horsepower rpm thrust etc None have changed meaning compared two-strokesits just way developed four-stroke thats different horsepow er 16 17000 rpm somehow still 16 hp now being developed 11000 rpm thing changes Typical HP Torque Curves 0 16 HP 7, 12in360 45 N -\ 12/7 V j H AII 5000 10000 15000 20000 25000 RPM get 16 horsepower out big tour-stroke engines smaller twostroke ones However its rpm get HP impor tant consideration four-stroker peaks about 12000 rpm two-strokes need 18000 22000 rpm Hardwood beams Floor fuel compartment ap balsa gussets front Cutout inbeams beveled clear glass fuselagefuse curvature glued fuse nose ring Original firewall cutout width beam mounts depth crank centerline Notched hardwood beams Heres group fliers modifies Great Planes Cosmic Wind quarter-scale kit use big 12 cu four-stroke engines now use racing Fuel tank location wedge foam Carburetor location Original firewall supports back beam mounts generally will front carburetor pictureand adds confusion what being done HP want thrust low-pitch prop will give you must keep prop diameter large load 5700 Typical 12 4-Stroke Curves 4Q0010000 12000 T T / / / 5000 Cheek cowl outline .OS Saito will require draincowl cutouts clear frontmount rocker boxes engine down absorb HP har ness workthe thrust pull airplane low-pitch prop will give lower airspeed fine light slowflying aircraft such Piper Cub shouldnt fly fast anyway Because slow sport flying applica HOTtion four-stroke started 120not hear propeller pitches over six inch es manufacturers literature N see things such 15 x 8 indurd o HP 16 x 6 etc Increasing propeller diameter loads engine same inch change pitch com bination isnt enough engine easily overrevs loses power see explanation further may damage both itself pocketbook overrev results valve float exactly what sounds like high enough rpm inertia springiness Some four-strokes hotter others peak HP occurs higher rpm However overall torque curve may well lower means wont lug large prop normal 10000 RPM UL RPM RON GE St 1 15000 Continued page 139 56 Model Aviation RC Old-Timers/Mathews Continued page 53 non-SAM-era models Hal deBolt tells will soon start column early RC designs Model Airplane News Id like some material Free Flight same approximate time frame am particularly turned PAA-Load both large small designs wartime goodies such Kid etc some really attractive sport-types such Pacificoaster last column Any photos would greatly appreciated Naturally puts would helpful well Two examples sort thing thinking Veco Sioux Bill Winters Midwest Sniffer enlargements published Flying Models few years back could get excited about sort conceptor impor tant youve tried itwould please drop line Dee B Mathews 8420 Nantucket Wichita KS 67212 RC Giant Scale/Beckman Continued page 55 Conclusion least conclusion Twins multi-engined models dont have considered terrible course theyre going compli cated turns out fail its pretty much same reasons models fall moral story learn failures apply lessons new project Pretty soon failures get few far between Bob Beckman 8248 Holly Grove Ct Manassas VA 22110 RC Pylon Racing/Hager Continued page 56 valve train reaches point valves dont follow bump cam may hit piston 14 x 10 prop its resulting rpm combination will keep well away since engines will run mid 8OOOs ground 10000 air diving three approved engines have redlines well past 12000 rpm Since racing need speed get pitch has increase because four-stroke engines now roughly 10000 rpm saw 15000 two-stroke 60 air Assuming 100 mph before seven-in pitch 15000 rpm now need 10 inches pitch 10000 rpm same speed 7 x 15000 approximately equals 10 x 10000 An added bonus larger prop efficient smaller thrust consistent rpm doesnt fall off turn since four-stroke lugs better meaning doesnt slow down much same ap plies takeoff climbing giving forgiving flight envelope can begin realize what have heard before propeller matching plane engine very important Back power torque Horsepower always combination torque rpm HP UE x RPM x k Torque twisting ability engine crankshaft have lugger always occurs lower rpm horsepow er peak 12 bigger engine has torque 60 half its size 12 generates torque much lower rpm Thats 12 11000 rpm 60 17000 rpm can both rated 16 horsepower just develop different set conditions Two-strokes have become powerhouses because easy increase rpm Look characteristics three engines see HP developed 12 cubic inch four-stroke 60 cubic inch two-stroke 45 cubic inch twostroke ducted fan engine deliver ap proximately 16 HP graph front column RH Torque climbs drops off approximately 2A HP max imum HP keeps climbing after torque drops because rpm still climbing torque drops faster rpm climbs HP starts drop hot engine sharper peaks types engines dif ficult set useful certain props Typically l2s use 13/15-inch prop 60s 11-inch 45s 5/9 inches 45s can actually develop HP cant use because dont have torque turn bigger props need larger prop higher-speed engine wont let engine get its horsepower peak doesnt matter horses liter ature says its rated Look curves 12 closely graph front column BH An engine doesnt develop HP automatically smaller prop just lets get up torque curve closer HP peak raised peak hotter engine may have shifted lower torque-curve anyway Horsepower Hop-up As long compare engines using same prop extra horsepower simple sounds since rpm wont go up itself unless changes made engine hop-up. engine de signed differently torque must creased some other way since rpm must go up takes torque easiest way power let rev. smaller prop less pitchbut allowed fore back torque increase THE LEADER IN COM PETITION NEW i 4 CYCLE THP DESIGN PRICE f 299 379 14479 15689 16989 NEW F 4 j NEW HIGH TECH AIRFOIL SECTION lOTO 20% INCREASE IN THRUST MFG OF SELECT HARD MAPLE WOOD WILL NOT FATIGUE LIKE SYNTHETICS FUEL PROOF HIGH LUSTER FINISH DIAPITCHPRICE 534149 634149 72833456179 833/,4568189 845667199 9456677199 104S667209 106W8W209 106EW219 ii46777/,7I,8229 115W229 11SEW239 1167239 124W279 125W279 1256279 1356349 1456459 1556659 164VzN989 16678969 PROPELLERS April1986 139 TAILORED HELICAL PITCH DEVELOPED TO GIVE MAXIMUM THRUST AT 4 CYCLE ENGINE RPM ALL THE LATEST TECHNIQUES USED ON OUR PRO SERIES 3 SEE BELOW PITCH THP 86 77 8 877 8 677 8 67 678 PRO SERIES 3 RC PYLON RACING SERIES 500 DIA PITCH PRICE 7SN 5/N279 8I 6/,7/z78 299 SERIES 400C 8 66777 289 9777/289 W WIDE BLADE EW EXTRA WIDE N NARROW 9 New Br SnehslDeimar Lightest weight hand start ready-to-mount englnesu th market 31 *27500 34 $34500 37- *35500 42 $37500 Engines Complete Nothing Extra Buy Choice points 31or CDI ignition %34-553 2a-SJEP&7-55s4a-65 NP42-553 Ioz. TSP Features Customized newest German engines parts lai t ting Salle aura Tap smoka Caritwelci Unkaga Ignition CH Elactronicala 48 V Ignition Pack ty Switch lt Hub etor Spk PIgs Waranty ca Faulty Parts Workmanship T G Mtg 857 HIgh Mountain Rd North Haldon NJ 07508 e 201 427-3845 HP a Bigger Engine. verb otcn. no way b Increase Compression old hot rod trick. allowed c More Breathing air fuel. bigger ... allowed may work engine cant draw fuel anyway d Better breathing larger valves passages etc.. allowed may actually hurt carb cain im proved well e The old hot cam. allowed very difficult anyway Changing cam timing may make things worse lower rpm other tricks like bigger carb Hot cams almost always used get breathing high rpm increases horsepower although peak torque may actually less before Hop-up isnt simple engine load ing such prop controlled brings up subject newer hotter engines make noticeably horsepower load rpm must come 1 Bigger carbs 2 Higher-rpm tuning design 3 Different-than-glow ignition 4 Hotter cams better breathing higher rpm 5 Supercharging tuned intake exhausts also type supercharging Youll notice increased compres sion old hot rod trick hasnt mentioned because glow ignition ralsing compression current engines will get trouble detona tion will slow down dont lose prop Higher-horsepower engine models introduced will somewhat dif ferent set up higher rpm special take ignition systems Extra horse power will mean complication expense manufacturers will keep bread-and-butter models available Because competition engines will stay very similar other performance information intended make experts out just help understand difference between hearsay buzzwords reality proven technical facts disposal keep engines competitive equiva lent Dont panic advertising high horsepower. talk usable horse power racing conditions care feeding Fours 1 Keep fuel tank close carb centerline possible 2 Read instructions break engine using rich needle valve setting 3 To start three approved engines open full throttle close choke giow off flip engine through two three times until fuel runs out exhaust close throttle open choke turn engine spinner back forth rid excess fuel light glow plug has hot because heavy elements fourstroke plugs turn prop spinner backwards slowly until feel back wards compression snap spinner back compression. engine will usual ly start didnt usually its still stiff storage oil engine must snappy free plug may hot enough Maybe need choke again difficult flood since fuel doesnt go through crankcase excess fuel can run out exhaust pipe side-mounted engines Always rock prop back forth clear excess fuel Fuel will compress can bend rodthis especially true use electric starter use dont choke much clear chamber first rocking spinner will need super battery starter use Several us have use electric starter yet still get one-flip starts follow sequence got one-to-two-flip starts last summer. four-strokers dont load up after idling long time 4 Tighten prop before flying session prop has moved after flight probably too lean engine detonating 5 Follow instructions set valves after first hour running once hour after valve clearance changes much after first hour proba bly running too lean pushing 6 Oil engine through overflow tube after flying once hour adjusting valves under rocker covers making sure runs down pushrod tubes oil cam 7 Use tachometer setting needle especially first time cant hear change much fourstrokes Typically back off 600-700 rpm first hour Enya OS especially least 300 rpm racing Saito appears less sensitive Learn engine/fuel tank combination tach just guidelines engine may bit different much different fuel system may drawing well should DONT TRUST YOUR EAR blow props engines trying tell you didnt set right Send tips ideas can pass readers See next month Bill Hager 706 Glen Haven Dr Conroe TX 77385 RC Helicopters/Jolly Continued page 57 pitch-curve adjustment both high low hovering memory idle-up pitch trim 25% range authority invert switch throttle hold two methods gyro control retract switch course dual rates aileron elevator functions sounds like lotits because 7H1 has just about everything Helicopter jock could want addition its laid out such fashion wont have trouble getting everything copter screaming around sky Airtronics also thoughtful enough add inhibit options invert throttle hold gyro throttle/rudder mix case dont want accidentally use perhaps youd like fly fixed-wing model radio test radio came equipped Air tronics new dual-conversion narrow-band receiver measures 2A x 1 x es 140 Model Aviation I
Edition: Model Aviation - 1986/04
Page Numbers: 56, 139, 140
Radio Control Pylon Racing Bill Hager ACTIVITY have just received letter Darwin Barrie Scottsdale Ari zona has area past several years has much rac ing looks though now changing As February 22-23 1986 will Formula race Darwin CD Biesemeyer Tool Co Phoenix Pylon Racing Association Arizona Model Aviators sponsors will waiting results guys seems though increasing amount -Scale Pylon Racing Northeast find quite few people raced living Ohio now racing Quarter Scale 85 started using four-stroke engines might add much success QSPRA newsletter comes following four-stroke engines FOUR-STROKING IT lot information being published about four-strokes Well try clarify technical points such power torque horsepower rpm thrust etc None have changed meaning compared two-strokesits just way developed four-stroke thats different horsepow er 16 17000 rpm somehow still 16 hp now being developed 11000 rpm thing changes Typical HP Torque Curves 0 16 HP 7, 12in360 45 N -\ 12/7 V j H AII 5000 10000 15000 20000 25000 RPM get 16 horsepower out big tour-stroke engines smaller twostroke ones However its rpm get HP impor tant consideration four-stroker peaks about 12000 rpm two-strokes need 18000 22000 rpm Hardwood beams Floor fuel compartment ap balsa gussets front Cutout inbeams beveled clear glass fuselagefuse curvature glued fuse nose ring Original firewall cutout width beam mounts depth crank centerline Notched hardwood beams Heres group fliers modifies Great Planes Cosmic Wind quarter-scale kit use big 12 cu four-stroke engines now use racing Fuel tank location wedge foam Carburetor location Original firewall supports back beam mounts generally will front carburetor pictureand adds confusion what being done HP want thrust low-pitch prop will give you must keep prop diameter large load 5700 Typical 12 4-Stroke Curves 4Q0010000 12000 T T / / / 5000 Cheek cowl outline .OS Saito will require draincowl cutouts clear frontmount rocker boxes engine down absorb HP har ness workthe thrust pull airplane low-pitch prop will give lower airspeed fine light slowflying aircraft such Piper Cub shouldnt fly fast anyway Because slow sport flying applica HOTtion four-stroke started 120not hear propeller pitches over six inch es manufacturers literature N see things such 15 x 8 indurd o HP 16 x 6 etc Increasing propeller diameter loads engine same inch change pitch com bination isnt enough engine easily overrevs loses power see explanation further may damage both itself pocketbook overrev results valve float exactly what sounds like high enough rpm inertia springiness Some four-strokes hotter others peak HP occurs higher rpm However overall torque curve may well lower means wont lug large prop normal 10000 RPM UL RPM RON GE St 1 15000 Continued page 139 56 Model Aviation RC Old-Timers/Mathews Continued page 53 non-SAM-era models Hal deBolt tells will soon start column early RC designs Model Airplane News Id like some material Free Flight same approximate time frame am particularly turned PAA-Load both large small designs wartime goodies such Kid etc some really attractive sport-types such Pacificoaster last column Any photos would greatly appreciated Naturally puts would helpful well Two examples sort thing thinking Veco Sioux Bill Winters Midwest Sniffer enlargements published Flying Models few years back could get excited about sort conceptor impor tant youve tried itwould please drop line Dee B Mathews 8420 Nantucket Wichita KS 67212 RC Giant Scale/Beckman Continued page 55 Conclusion least conclusion Twins multi-engined models dont have considered terrible course theyre going compli cated turns out fail its pretty much same reasons models fall moral story learn failures apply lessons new project Pretty soon failures get few far between Bob Beckman 8248 Holly Grove Ct Manassas VA 22110 RC Pylon Racing/Hager Continued page 56 valve train reaches point valves dont follow bump cam may hit piston 14 x 10 prop its resulting rpm combination will keep well away since engines will run mid 8OOOs ground 10000 air diving three approved engines have redlines well past 12000 rpm Since racing need speed get pitch has increase because four-stroke engines now roughly 10000 rpm saw 15000 two-stroke 60 air Assuming 100 mph before seven-in pitch 15000 rpm now need 10 inches pitch 10000 rpm same speed 7 x 15000 approximately equals 10 x 10000 An added bonus larger prop efficient smaller thrust consistent rpm doesnt fall off turn since four-stroke lugs better meaning doesnt slow down much same ap plies takeoff climbing giving forgiving flight envelope can begin realize what have heard before propeller matching plane engine very important Back power torque Horsepower always combination torque rpm HP UE x RPM x k Torque twisting ability engine crankshaft have lugger always occurs lower rpm horsepow er peak 12 bigger engine has torque 60 half its size 12 generates torque much lower rpm Thats 12 11000 rpm 60 17000 rpm can both rated 16 horsepower just develop different set conditions Two-strokes have become powerhouses because easy increase rpm Look characteristics three engines see HP developed 12 cubic inch four-stroke 60 cubic inch two-stroke 45 cubic inch twostroke ducted fan engine deliver ap proximately 16 HP graph front column RH Torque climbs drops off approximately 2A HP max imum HP keeps climbing after torque drops because rpm still climbing torque drops faster rpm climbs HP starts drop hot engine sharper peaks types engines dif ficult set useful certain props Typically l2s use 13/15-inch prop 60s 11-inch 45s 5/9 inches 45s can actually develop HP cant use because dont have torque turn bigger props need larger prop higher-speed engine wont let engine get its horsepower peak doesnt matter horses liter ature says its rated Look curves 12 closely graph front column BH An engine doesnt develop HP automatically smaller prop just lets get up torque curve closer HP peak raised peak hotter engine may have shifted lower torque-curve anyway Horsepower Hop-up As long compare engines using same prop extra horsepower simple sounds since rpm wont go up itself unless changes made engine hop-up. engine de signed differently torque must creased some other way since rpm must go up takes torque easiest way power let rev. smaller prop less pitchbut allowed fore back torque increase THE LEADER IN COM PETITION NEW i 4 CYCLE THP DESIGN PRICE f 299 379 14479 15689 16989 NEW F 4 j NEW HIGH TECH AIRFOIL SECTION lOTO 20% INCREASE IN THRUST MFG OF SELECT HARD MAPLE WOOD WILL NOT FATIGUE LIKE SYNTHETICS FUEL PROOF HIGH LUSTER FINISH DIAPITCHPRICE 534149 634149 72833456179 833/,4568189 845667199 9456677199 104S667209 106W8W209 106EW219 ii46777/,7I,8229 115W229 11SEW239 1167239 124W279 125W279 1256279 1356349 1456459 1556659 164VzN989 16678969 PROPELLERS April1986 139 TAILORED HELICAL PITCH DEVELOPED TO GIVE MAXIMUM THRUST AT 4 CYCLE ENGINE RPM ALL THE LATEST TECHNIQUES USED ON OUR PRO SERIES 3 SEE BELOW PITCH THP 86 77 8 877 8 677 8 67 678 PRO SERIES 3 RC PYLON RACING SERIES 500 DIA PITCH PRICE 7SN 5/N279 8I 6/,7/z78 299 SERIES 400C 8 66777 289 9777/289 W WIDE BLADE EW EXTRA WIDE N NARROW 9 New Br SnehslDeimar Lightest weight hand start ready-to-mount englnesu th market 31 *27500 34 $34500 37- *35500 42 $37500 Engines Complete Nothing Extra Buy Choice points 31or CDI ignition %34-553 2a-SJEP&7-55s4a-65 NP42-553 Ioz. TSP Features Customized newest German engines parts lai t ting Salle aura Tap smoka Caritwelci Unkaga Ignition CH Elactronicala 48 V Ignition Pack ty Switch lt Hub etor Spk PIgs Waranty ca Faulty Parts Workmanship T G Mtg 857 HIgh Mountain Rd North Haldon NJ 07508 e 201 427-3845 HP a Bigger Engine. verb otcn. no way b Increase Compression old hot rod trick. allowed c More Breathing air fuel. bigger ... allowed may work engine cant draw fuel anyway d Better breathing larger valves passages etc.. allowed may actually hurt carb cain im proved well e The old hot cam. allowed very difficult anyway Changing cam timing may make things worse lower rpm other tricks like bigger carb Hot cams almost always used get breathing high rpm increases horsepower although peak torque may actually less before Hop-up isnt simple engine load ing such prop controlled brings up subject newer hotter engines make noticeably horsepower load rpm must come 1 Bigger carbs 2 Higher-rpm tuning design 3 Different-than-glow ignition 4 Hotter cams better breathing higher rpm 5 Supercharging tuned intake exhausts also type supercharging Youll notice increased compres sion old hot rod trick hasnt mentioned because glow ignition ralsing compression current engines will get trouble detona tion will slow down dont lose prop Higher-horsepower engine models introduced will somewhat dif ferent set up higher rpm special take ignition systems Extra horse power will mean complication expense manufacturers will keep bread-and-butter models available Because competition engines will stay very similar other performance information intended make experts out just help understand difference between hearsay buzzwords reality proven technical facts disposal keep engines competitive equiva lent Dont panic advertising high horsepower. talk usable horse power racing conditions care feeding Fours 1 Keep fuel tank close carb centerline possible 2 Read instructions break engine using rich needle valve setting 3 To start three approved engines open full throttle close choke giow off flip engine through two three times until fuel runs out exhaust close throttle open choke turn engine spinner back forth rid excess fuel light glow plug has hot because heavy elements fourstroke plugs turn prop spinner backwards slowly until feel back wards compression snap spinner back compression. engine will usual ly start didnt usually its still stiff storage oil engine must snappy free plug may hot enough Maybe need choke again difficult flood since fuel doesnt go through crankcase excess fuel can run out exhaust pipe side-mounted engines Always rock prop back forth clear excess fuel Fuel will compress can bend rodthis especially true use electric starter use dont choke much clear chamber first rocking spinner will need super battery starter use Several us have use electric starter yet still get one-flip starts follow sequence got one-to-two-flip starts last summer. four-strokers dont load up after idling long time 4 Tighten prop before flying session prop has moved after flight probably too lean engine detonating 5 Follow instructions set valves after first hour running once hour after valve clearance changes much after first hour proba bly running too lean pushing 6 Oil engine through overflow tube after flying once hour adjusting valves under rocker covers making sure runs down pushrod tubes oil cam 7 Use tachometer setting needle especially first time cant hear change much fourstrokes Typically back off 600-700 rpm first hour Enya OS especially least 300 rpm racing Saito appears less sensitive Learn engine/fuel tank combination tach just guidelines engine may bit different much different fuel system may drawing well should DONT TRUST YOUR EAR blow props engines trying tell you didnt set right Send tips ideas can pass readers See next month Bill Hager 706 Glen Haven Dr Conroe TX 77385 RC Helicopters/Jolly Continued page 57 pitch-curve adjustment both high low hovering memory idle-up pitch trim 25% range authority invert switch throttle hold two methods gyro control retract switch course dual rates aileron elevator functions sounds like lotits because 7H1 has just about everything Helicopter jock could want addition its laid out such fashion wont have trouble getting everything copter screaming around sky Airtronics also thoughtful enough add inhibit options invert throttle hold gyro throttle/rudder mix case dont want accidentally use perhaps youd like fly fixed-wing model radio test radio came equipped Air tronics new dual-conversion narrow-band receiver measures 2A x 1 x es 140 Model Aviation I