Radio Control Pylon Racing Bill Hager SHORT WHILE AGO received paper FAI RC Pylon Racing written Paul Bowman England Joint League winner 1983 goves over some very basic important points about FAI event think will some help just getting started might something experts So go Weak Links power plant miniature Pylon Racer consists numerous components may considered form pro gressive chain As know chain ly strong its weakest link powerplants models example first-class engine will appear perform below average fitted appropriate inefficient propeller propeller being weak link chain therefore necessary establish common strength level efficiency throughout powerplant before its potential can realized Few competitors FAI RC Pylon today appear take approach Instead seem intent tuning engines very high level hoping will compensate weak links systems Unfortunately generally case Having estab lished common level efficiency throughout powerplant attention must given make component parts totally reliable furthermore replaceable event crash system may replaced part whole required especially rele vant propellers concerned During 1983 developed setup using standard OPS equipment use some other type engine much follow ing information will remain interest Although system fastest 1983 BMPRA British Model Pylon Racing Assn circuit proved consistent attaining four final* places semifinal* five meetings held general true say fastest model gaining finai place will win day qualifying finaland importantly semi finalis question out-and-out speed rather matter reliability An insufficient number completed heats due lack reliability far frequently responsible failure qualify semi-finals inability attain fast times Reliability primarily far important out-and-out speed will noticed reli ability achieved faster times will follow next few paragraphs shall out line extract reliable competi tive performance standard OPS engine utilizing optimum settings have established over past seasons hope information will use interested FAI Pylon Racing regardless make engine used especially newcomers sport Use infor mation will give reliable base allowing competitors concentrate numer ous other factors go together make successful race Propellers importance pro peller cannot overstated propeller major factor directly affecting overall performance powerplant consistent results essential propeller resembles next close ly possible Wooden propellers prove very satisfactory field differ much grain density must therefore look manmade materials such glass fiber carbon fiber two suitable materials currently available accurate copies may produced resulting consistent performance Paul uses props following sizes 7-4 inches diameter 7 inches pitch oper ating range between 22500 23500 ground rpm BH propellers require minimum amount work ing carried out before ready race After removal flash bal ancing may however worked slightly thinner section little extra efficiency Phrg The glow plug engine basically compression ignition engine glow plug simply aids compressive forces heating combustible gases point detonation finer wire element hotter plug becomes hence further advancement ignition tim ing optimum plug OPS engine has found K&B 1 L standard K&B long-reach plug available Irvine Engines very hot plug 1 1A-volt type producing wellContinued page 138 Nadrchai/Kunes team Mustang FAi racer years Grand PrIx race heid Czechoslovakia L finished third winners Grand Prix Ciub 20 races R 1st P SmoothylS King 2nd i ParislP Matocha 3rd M GriggslR Buck others identit led Note typical international Contests winners get Diplomas trophies also merchandise 52Model Aviation A Laurie Raczo Great Britain Club 20 racer Grand Prix races Craft looks like slightiyoversize Quarter Midget Note muffler AlTENTION ERS common experience nor mal temperatures days first flight good after first charge day doesnt seem good follow never viewed phenomenon being temperature-related often refer red warm-up However situation changes cold-storage conditions described above first charge really warm-up may second third no question about first very cold flight likely quite bit slug gish second possibly third Thereafter fingers may freezing motor battery behavior seems perfectly normal because think batteries warm hot use have forgotten cold week garage once have ex perienced significant power increase flight batteries warmed up time Id expect some drop power due normal charge depletion way winter air around best air year flying may uncomfortable cold dry dense air sure makes plane fly great Models seem light buoyant likely have significantly longer motor runs because seems plane weighs less less power expended keeping plane up power available make plane go may have guessed condition has dual opposite worst flying air thin humid hot air summer whenever models Electric affected both extremes Another incidental before leaving subject planes stored garage flight box kept inside nor mal temperatures contains lead/acid tractor-size battery fuel prefer just keep familiar temperatures guess its memories hard car starts cold mornings Finally readers loners immediate areas some areas enjoying small groups fliers just two three persons Id like encourage scattered groups few fliers consider hosting Electric Fly-in upcoming year column will help announcing intentions Dont worry about making big deal Forget events Forget prizes Forget anything sounds like work except course sending information incom ing inquiries Just make come fly us day weekend have share yourselves Electric inter ests field No doubt several loners small groups within easy traveling distance just dying find some else share interests Think over send informa tion Remember takes few months get print get moving now Happy Landings Bob Kopski 25 West End Dr Lans dale PA 19446 RC Pylon Racing/Hager Continued page 52 advanced ignition Care must taken starting engine regulate current flow through element order prevent damage Having fine element plug easily destroyed lean mixture setting state plug element good dication running conditions within engine especially useful during racing difficult distinguish sound ones own engine ele ment after race found intact undistorted mixture probably set too rich element found tact slightly distorted mixture probably -correct setting plug must changed race main tain performance element found intact found severely distorted mixture probably too lean Great care must taken using plug lean mixture setting may cause element become detached resulting irrevocable damage piston/liner cylinder head Head clearance volume available combustion chamber top dead center piston stroke directly related clearance between piston crown cylinder head squish band Continued page 140 138Model Aviation L5NAI~ hinge allows control surface removal tools Driuuv~lost pins problems PATENTpainting PENDINGcoveringrepair transportation storage etc Scale Appearance InsertSimple Assembly 3 SIZES No Slots1*4s-6 $335 38-6 $445 Rotate 900No Pins12-6 $495 EPOXY GLASS COWLS FOR NOSEN PICA SW SIORGAM BALSA USA PLATT CONCEPT FLEET HOSTETLER ACM T-CAAFT SHEBER P/iTS & SCALE SUPER CUB FOKEER 0-7 BOEING P- 72 P-2B F4B2 MBE SPARROW HAWK GEE BEE MOO Y MACBR/ENS TURBULENT CHRISTEN EAGLE BRISIGHEL LAS STAROUS TEA II A SCALE J3BI BABY FLYBABY AIRCAMPER PILOT JUAGMA N/V 735 SCALE 7/4 SCALE DECATHALON PIPER PA- YB N OTHERS WHEEL PANTS FOR C/TA BR/A STAROUS TEA II P/iTS SKYBOL T L/BERTYSPOAT CHRISTEN EAGLE PSEHAWE STEARMAN SIINSON SR-S MULLIGAN N OTHERS BRAZEDO HEAT-ThEATED WIRE GEARS& CADANES lARGE SCALE PLANS AVAILABLE Send $100 latest list supply Modelers fiberglass parts plansWrite cell us T b D FIBERGLASS SPECIALTIES 30925 BWCK GARDEN CflY MI 48735 PHONE 313 421-6356 Power Soar New Heights Send self-addressed stamped envelope catalog ap plication notes Leisure 11 Deerspring/IrvinelCA 92714 LT-50 GEAR MOTOR Leisures Gear Drive conversion 31 powerful LT-50 develops up 2 lbs static trhrust Gear Drive also features ball bearing Delrinlbrass gearing glass loaded polycarbonate housing Worn Out R/C Buyers Guide has gotten bit dog-eared thats understandable after designed used year long planning projects locating hard-to-find products getting ahead hobby hundreds better reasons get New 8th Edi tion NEW PRODUCTS Since last publication staff Guide has compiled several hundred new products Toledo other major R/C shows Theyre new 8th edition fully described illustrated Hard-to-find specialty parts materials bogging down pro ject Look new R/C Buyers Guide along nearly other R/C Aircraft Boat Car related product commercially available Over 2500 New hobby Youll find Guide mind-jogging excursion seemingly limitless possibilities R/C wild machines its devotees Get new Radio Control Buyers Guide 8th Edition Its R/C reference book youll read Mow Only S695 See Hobby Dealer dealer send $695 plus $200 postage handling Ii BOYNTON & ASSOCIATES INC i C~ON HOUSE CLIFTON VA 22024 change clearance will result change compression ratio engine therefore compression ratio may regarded terms head clearance Too much clearance will lower compression ratio retarding igni tion causing subsequent loss power condition engine will difficult run pipe will require lean mixture setting maintain rpm Too little clearance will increase compression ratio thereby highly advanc ing ignition also causing subse quent loss power condition engine will run pipe will require rich mixture setting maintain rpm prevent overheating OPS engine have found 0012 inches opti mum clearance giving reliable com petitive performance weathers conditions head clearance dividual engine must first established using depth gauge similar instrument may adjusted optimum inserting shims under head required Tuned-length exhaust pipe Due design two-stroke engine during cycle unburnt gases lost cylinder exhaust system tuned-length exhaust pipe simple reso nant device used improve perfor mance two-stroke engine pushing back cylinder some un burnt gases resonant frequency tuned pipe partly dependent its length must matched operat ing rpm engine ease reso nant length pipe normally regard ed terms length glow plug point widest diameter pipe decrease tuned length will raise operating rpm pipe crease tuned length will lower operating rpm pipe optimum length OPS unsilenced pipe OPS silenced pipe its rear can re moved has found 2325cm corresponds operating range between 22500 23500 ground rpm However reasons engine run below its best performance therefore suggest initial tuned length 24cm reducing optimum 025cm stages little power required Exhaust manifold standard OPS exhaust manifold has proved very satisfactory have therefore replaced component short mani fold machined solid aluminum bar joint between manifold tuned pipe best effected using silicon rubber tubing allowing gap 3mm expan sion movement between manifold pipe durable silicon rubber tubing currently available manufactured Micro Mold tubing will normally last six flights should replaced frequent intervals will prevent perforation exposed area hot exhaust gases addition above have available similar manifolds suited OS K&B engines continued * Paul Bowman refers finals semi-finals because number European countries including Great Britain modify FAL flying rules use FAI system selecting semifinalists Depending number heats flown competitor may drop worst score Typically scores counted would four out four four out five five out seven etc depending number heats flown organiz ers rank competitors eight top being chosen semi-final Two heats flown semi-finals fliers four fastest times qualify forthe final Places five through eight ranked semi-final times top four ranked final times top fliers tend regard heats almost practice semi-final final real competition Next month will have full report 84 Grand Prix races held Czechoslovakia conclusion Paul Bowmans article FAI racing See next month Bill Hager 706 Glen Haven Dr Conroe TX 77385 read about Model Aviation writing advertisers mention 140Model Aviation
Edition: Model Aviation - 1985/02
Page Numbers: 52, 138, 140
Radio Control Pylon Racing Bill Hager SHORT WHILE AGO received paper FAI RC Pylon Racing written Paul Bowman England Joint League winner 1983 goves over some very basic important points about FAI event think will some help just getting started might something experts So go Weak Links power plant miniature Pylon Racer consists numerous components may considered form pro gressive chain As know chain ly strong its weakest link powerplants models example first-class engine will appear perform below average fitted appropriate inefficient propeller propeller being weak link chain therefore necessary establish common strength level efficiency throughout powerplant before its potential can realized Few competitors FAI RC Pylon today appear take approach Instead seem intent tuning engines very high level hoping will compensate weak links systems Unfortunately generally case Having estab lished common level efficiency throughout powerplant attention must given make component parts totally reliable furthermore replaceable event crash system may replaced part whole required especially rele vant propellers concerned During 1983 developed setup using standard OPS equipment use some other type engine much follow ing information will remain interest Although system fastest 1983 BMPRA British Model Pylon Racing Assn circuit proved consistent attaining four final* places semifinal* five meetings held general true say fastest model gaining finai place will win day qualifying finaland importantly semi finalis question out-and-out speed rather matter reliability An insufficient number completed heats due lack reliability far frequently responsible failure qualify semi-finals inability attain fast times Reliability primarily far important out-and-out speed will noticed reli ability achieved faster times will follow next few paragraphs shall out line extract reliable competi tive performance standard OPS engine utilizing optimum settings have established over past seasons hope information will use interested FAI Pylon Racing regardless make engine used especially newcomers sport Use infor mation will give reliable base allowing competitors concentrate numer ous other factors go together make successful race Propellers importance pro peller cannot overstated propeller major factor directly affecting overall performance powerplant consistent results essential propeller resembles next close ly possible Wooden propellers prove very satisfactory field differ much grain density must therefore look manmade materials such glass fiber carbon fiber two suitable materials currently available accurate copies may produced resulting consistent performance Paul uses props following sizes 7-4 inches diameter 7 inches pitch oper ating range between 22500 23500 ground rpm BH propellers require minimum amount work ing carried out before ready race After removal flash bal ancing may however worked slightly thinner section little extra efficiency Phrg The glow plug engine basically compression ignition engine glow plug simply aids compressive forces heating combustible gases point detonation finer wire element hotter plug becomes hence further advancement ignition tim ing optimum plug OPS engine has found K&B 1 L standard K&B long-reach plug available Irvine Engines very hot plug 1 1A-volt type producing wellContinued page 138 Nadrchai/Kunes team Mustang FAi racer years Grand PrIx race heid Czechoslovakia L finished third winners Grand Prix Ciub 20 races R 1st P SmoothylS King 2nd i ParislP Matocha 3rd M GriggslR Buck others identit led Note typical international Contests winners get Diplomas trophies also merchandise 52Model Aviation A Laurie Raczo Great Britain Club 20 racer Grand Prix races Craft looks like slightiyoversize Quarter Midget Note muffler AlTENTION ERS common experience nor mal temperatures days first flight good after first charge day doesnt seem good follow never viewed phenomenon being temperature-related often refer red warm-up However situation changes cold-storage conditions described above first charge really warm-up may second third no question about first very cold flight likely quite bit slug gish second possibly third Thereafter fingers may freezing motor battery behavior seems perfectly normal because think batteries warm hot use have forgotten cold week garage once have ex perienced significant power increase flight batteries warmed up time Id expect some drop power due normal charge depletion way winter air around best air year flying may uncomfortable cold dry dense air sure makes plane fly great Models seem light buoyant likely have significantly longer motor runs because seems plane weighs less less power expended keeping plane up power available make plane go may have guessed condition has dual opposite worst flying air thin humid hot air summer whenever models Electric affected both extremes Another incidental before leaving subject planes stored garage flight box kept inside nor mal temperatures contains lead/acid tractor-size battery fuel prefer just keep familiar temperatures guess its memories hard car starts cold mornings Finally readers loners immediate areas some areas enjoying small groups fliers just two three persons Id like encourage scattered groups few fliers consider hosting Electric Fly-in upcoming year column will help announcing intentions Dont worry about making big deal Forget events Forget prizes Forget anything sounds like work except course sending information incom ing inquiries Just make come fly us day weekend have share yourselves Electric inter ests field No doubt several loners small groups within easy traveling distance just dying find some else share interests Think over send informa tion Remember takes few months get print get moving now Happy Landings Bob Kopski 25 West End Dr Lans dale PA 19446 RC Pylon Racing/Hager Continued page 52 advanced ignition Care must taken starting engine regulate current flow through element order prevent damage Having fine element plug easily destroyed lean mixture setting state plug element good dication running conditions within engine especially useful during racing difficult distinguish sound ones own engine ele ment after race found intact undistorted mixture probably set too rich element found tact slightly distorted mixture probably -correct setting plug must changed race main tain performance element found intact found severely distorted mixture probably too lean Great care must taken using plug lean mixture setting may cause element become detached resulting irrevocable damage piston/liner cylinder head Head clearance volume available combustion chamber top dead center piston stroke directly related clearance between piston crown cylinder head squish band Continued page 140 138Model Aviation L5NAI~ hinge allows control surface removal tools Driuuv~lost pins problems PATENTpainting PENDINGcoveringrepair transportation storage etc Scale Appearance InsertSimple Assembly 3 SIZES No Slots1*4s-6 $335 38-6 $445 Rotate 900No Pins12-6 $495 EPOXY GLASS COWLS FOR NOSEN PICA SW SIORGAM BALSA USA PLATT CONCEPT FLEET HOSTETLER ACM T-CAAFT SHEBER P/iTS & SCALE SUPER CUB FOKEER 0-7 BOEING P- 72 P-2B F4B2 MBE SPARROW HAWK GEE BEE MOO Y MACBR/ENS TURBULENT CHRISTEN EAGLE BRISIGHEL LAS STAROUS TEA II A SCALE J3BI BABY FLYBABY AIRCAMPER PILOT JUAGMA N/V 735 SCALE 7/4 SCALE DECATHALON PIPER PA- YB N OTHERS WHEEL PANTS FOR C/TA BR/A STAROUS TEA II P/iTS SKYBOL T L/BERTYSPOAT CHRISTEN EAGLE PSEHAWE STEARMAN SIINSON SR-S MULLIGAN N OTHERS BRAZEDO HEAT-ThEATED WIRE GEARS& CADANES lARGE SCALE PLANS AVAILABLE Send $100 latest list supply Modelers fiberglass parts plansWrite cell us T b D FIBERGLASS SPECIALTIES 30925 BWCK GARDEN CflY MI 48735 PHONE 313 421-6356 Power Soar New Heights Send self-addressed stamped envelope catalog ap plication notes Leisure 11 Deerspring/IrvinelCA 92714 LT-50 GEAR MOTOR Leisures Gear Drive conversion 31 powerful LT-50 develops up 2 lbs static trhrust Gear Drive also features ball bearing Delrinlbrass gearing glass loaded polycarbonate housing Worn Out R/C Buyers Guide has gotten bit dog-eared thats understandable after designed used year long planning projects locating hard-to-find products getting ahead hobby hundreds better reasons get New 8th Edi tion NEW PRODUCTS Since last publication staff Guide has compiled several hundred new products Toledo other major R/C shows Theyre new 8th edition fully described illustrated Hard-to-find specialty parts materials bogging down pro ject Look new R/C Buyers Guide along nearly other R/C Aircraft Boat Car related product commercially available Over 2500 New hobby Youll find Guide mind-jogging excursion seemingly limitless possibilities R/C wild machines its devotees Get new Radio Control Buyers Guide 8th Edition Its R/C reference book youll read Mow Only S695 See Hobby Dealer dealer send $695 plus $200 postage handling Ii BOYNTON & ASSOCIATES INC i C~ON HOUSE CLIFTON VA 22024 change clearance will result change compression ratio engine therefore compression ratio may regarded terms head clearance Too much clearance will lower compression ratio retarding igni tion causing subsequent loss power condition engine will difficult run pipe will require lean mixture setting maintain rpm Too little clearance will increase compression ratio thereby highly advanc ing ignition also causing subse quent loss power condition engine will run pipe will require rich mixture setting maintain rpm prevent overheating OPS engine have found 0012 inches opti mum clearance giving reliable com petitive performance weathers conditions head clearance dividual engine must first established using depth gauge similar instrument may adjusted optimum inserting shims under head required Tuned-length exhaust pipe Due design two-stroke engine during cycle unburnt gases lost cylinder exhaust system tuned-length exhaust pipe simple reso nant device used improve perfor mance two-stroke engine pushing back cylinder some un burnt gases resonant frequency tuned pipe partly dependent its length must matched operat ing rpm engine ease reso nant length pipe normally regard ed terms length glow plug point widest diameter pipe decrease tuned length will raise operating rpm pipe crease tuned length will lower operating rpm pipe optimum length OPS unsilenced pipe OPS silenced pipe its rear can re moved has found 2325cm corresponds operating range between 22500 23500 ground rpm However reasons engine run below its best performance therefore suggest initial tuned length 24cm reducing optimum 025cm stages little power required Exhaust manifold standard OPS exhaust manifold has proved very satisfactory have therefore replaced component short mani fold machined solid aluminum bar joint between manifold tuned pipe best effected using silicon rubber tubing allowing gap 3mm expan sion movement between manifold pipe durable silicon rubber tubing currently available manufactured Micro Mold tubing will normally last six flights should replaced frequent intervals will prevent perforation exposed area hot exhaust gases addition above have available similar manifolds suited OS K&B engines continued * Paul Bowman refers finals semi-finals because number European countries including Great Britain modify FAL flying rules use FAI system selecting semifinalists Depending number heats flown competitor may drop worst score Typically scores counted would four out four four out five five out seven etc depending number heats flown organiz ers rank competitors eight top being chosen semi-final Two heats flown semi-finals fliers four fastest times qualify forthe final Places five through eight ranked semi-final times top four ranked final times top fliers tend regard heats almost practice semi-final final real competition Next month will have full report 84 Grand Prix races held Czechoslovakia conclusion Paul Bowmans article FAI racing See next month Bill Hager 706 Glen Haven Dr Conroe TX 77385 read about Model Aviation writing advertisers mention 140Model Aviation
Edition: Model Aviation - 1985/02
Page Numbers: 52, 138, 140
Radio Control Pylon Racing Bill Hager SHORT WHILE AGO received paper FAI RC Pylon Racing written Paul Bowman England Joint League winner 1983 goves over some very basic important points about FAI event think will some help just getting started might something experts So go Weak Links power plant miniature Pylon Racer consists numerous components may considered form pro gressive chain As know chain ly strong its weakest link powerplants models example first-class engine will appear perform below average fitted appropriate inefficient propeller propeller being weak link chain therefore necessary establish common strength level efficiency throughout powerplant before its potential can realized Few competitors FAI RC Pylon today appear take approach Instead seem intent tuning engines very high level hoping will compensate weak links systems Unfortunately generally case Having estab lished common level efficiency throughout powerplant attention must given make component parts totally reliable furthermore replaceable event crash system may replaced part whole required especially rele vant propellers concerned During 1983 developed setup using standard OPS equipment use some other type engine much follow ing information will remain interest Although system fastest 1983 BMPRA British Model Pylon Racing Assn circuit proved consistent attaining four final* places semifinal* five meetings held general true say fastest model gaining finai place will win day qualifying finaland importantly semi finalis question out-and-out speed rather matter reliability An insufficient number completed heats due lack reliability far frequently responsible failure qualify semi-finals inability attain fast times Reliability primarily far important out-and-out speed will noticed reli ability achieved faster times will follow next few paragraphs shall out line extract reliable competi tive performance standard OPS engine utilizing optimum settings have established over past seasons hope information will use interested FAI Pylon Racing regardless make engine used especially newcomers sport Use infor mation will give reliable base allowing competitors concentrate numer ous other factors go together make successful race Propellers importance pro peller cannot overstated propeller major factor directly affecting overall performance powerplant consistent results essential propeller resembles next close ly possible Wooden propellers prove very satisfactory field differ much grain density must therefore look manmade materials such glass fiber carbon fiber two suitable materials currently available accurate copies may produced resulting consistent performance Paul uses props following sizes 7-4 inches diameter 7 inches pitch oper ating range between 22500 23500 ground rpm BH propellers require minimum amount work ing carried out before ready race After removal flash bal ancing may however worked slightly thinner section little extra efficiency Phrg The glow plug engine basically compression ignition engine glow plug simply aids compressive forces heating combustible gases point detonation finer wire element hotter plug becomes hence further advancement ignition tim ing optimum plug OPS engine has found K&B 1 L standard K&B long-reach plug available Irvine Engines very hot plug 1 1A-volt type producing wellContinued page 138 Nadrchai/Kunes team Mustang FAi racer years Grand PrIx race heid Czechoslovakia L finished third winners Grand Prix Ciub 20 races R 1st P SmoothylS King 2nd i ParislP Matocha 3rd M GriggslR Buck others identit led Note typical international Contests winners get Diplomas trophies also merchandise 52Model Aviation A Laurie Raczo Great Britain Club 20 racer Grand Prix races Craft looks like slightiyoversize Quarter Midget Note muffler AlTENTION ERS common experience nor mal temperatures days first flight good after first charge day doesnt seem good follow never viewed phenomenon being temperature-related often refer red warm-up However situation changes cold-storage conditions described above first charge really warm-up may second third no question about first very cold flight likely quite bit slug gish second possibly third Thereafter fingers may freezing motor battery behavior seems perfectly normal because think batteries warm hot use have forgotten cold week garage once have ex perienced significant power increase flight batteries warmed up time Id expect some drop power due normal charge depletion way winter air around best air year flying may uncomfortable cold dry dense air sure makes plane fly great Models seem light buoyant likely have significantly longer motor runs because seems plane weighs less less power expended keeping plane up power available make plane go may have guessed condition has dual opposite worst flying air thin humid hot air summer whenever models Electric affected both extremes Another incidental before leaving subject planes stored garage flight box kept inside nor mal temperatures contains lead/acid tractor-size battery fuel prefer just keep familiar temperatures guess its memories hard car starts cold mornings Finally readers loners immediate areas some areas enjoying small groups fliers just two three persons Id like encourage scattered groups few fliers consider hosting Electric Fly-in upcoming year column will help announcing intentions Dont worry about making big deal Forget events Forget prizes Forget anything sounds like work except course sending information incom ing inquiries Just make come fly us day weekend have share yourselves Electric inter ests field No doubt several loners small groups within easy traveling distance just dying find some else share interests Think over send informa tion Remember takes few months get print get moving now Happy Landings Bob Kopski 25 West End Dr Lans dale PA 19446 RC Pylon Racing/Hager Continued page 52 advanced ignition Care must taken starting engine regulate current flow through element order prevent damage Having fine element plug easily destroyed lean mixture setting state plug element good dication running conditions within engine especially useful during racing difficult distinguish sound ones own engine ele ment after race found intact undistorted mixture probably set too rich element found tact slightly distorted mixture probably -correct setting plug must changed race main tain performance element found intact found severely distorted mixture probably too lean Great care must taken using plug lean mixture setting may cause element become detached resulting irrevocable damage piston/liner cylinder head Head clearance volume available combustion chamber top dead center piston stroke directly related clearance between piston crown cylinder head squish band Continued page 140 138Model Aviation L5NAI~ hinge allows control surface removal tools Driuuv~lost pins problems PATENTpainting PENDINGcoveringrepair transportation storage etc Scale Appearance InsertSimple Assembly 3 SIZES No Slots1*4s-6 $335 38-6 $445 Rotate 900No Pins12-6 $495 EPOXY GLASS COWLS FOR NOSEN PICA SW SIORGAM BALSA USA PLATT CONCEPT FLEET HOSTETLER ACM T-CAAFT SHEBER P/iTS & SCALE SUPER CUB FOKEER 0-7 BOEING P- 72 P-2B F4B2 MBE SPARROW HAWK GEE BEE MOO Y MACBR/ENS TURBULENT CHRISTEN EAGLE BRISIGHEL LAS STAROUS TEA II A SCALE J3BI BABY FLYBABY AIRCAMPER PILOT JUAGMA N/V 735 SCALE 7/4 SCALE DECATHALON PIPER PA- YB N OTHERS WHEEL PANTS FOR C/TA BR/A STAROUS TEA II P/iTS SKYBOL T L/BERTYSPOAT CHRISTEN EAGLE PSEHAWE STEARMAN SIINSON SR-S MULLIGAN N OTHERS BRAZEDO HEAT-ThEATED WIRE GEARS& CADANES lARGE SCALE PLANS AVAILABLE Send $100 latest list supply Modelers fiberglass parts plansWrite cell us T b D FIBERGLASS SPECIALTIES 30925 BWCK GARDEN CflY MI 48735 PHONE 313 421-6356 Power Soar New Heights Send self-addressed stamped envelope catalog ap plication notes Leisure 11 Deerspring/IrvinelCA 92714 LT-50 GEAR MOTOR Leisures Gear Drive conversion 31 powerful LT-50 develops up 2 lbs static trhrust Gear Drive also features ball bearing Delrinlbrass gearing glass loaded polycarbonate housing Worn Out R/C Buyers Guide has gotten bit dog-eared thats understandable after designed used year long planning projects locating hard-to-find products getting ahead hobby hundreds better reasons get New 8th Edi tion NEW PRODUCTS Since last publication staff Guide has compiled several hundred new products Toledo other major R/C shows Theyre new 8th edition fully described illustrated Hard-to-find specialty parts materials bogging down pro ject Look new R/C Buyers Guide along nearly other R/C Aircraft Boat Car related product commercially available Over 2500 New hobby Youll find Guide mind-jogging excursion seemingly limitless possibilities R/C wild machines its devotees Get new Radio Control Buyers Guide 8th Edition Its R/C reference book youll read Mow Only S695 See Hobby Dealer dealer send $695 plus $200 postage handling Ii BOYNTON & ASSOCIATES INC i C~ON HOUSE CLIFTON VA 22024 change clearance will result change compression ratio engine therefore compression ratio may regarded terms head clearance Too much clearance will lower compression ratio retarding igni tion causing subsequent loss power condition engine will difficult run pipe will require lean mixture setting maintain rpm Too little clearance will increase compression ratio thereby highly advanc ing ignition also causing subse quent loss power condition engine will run pipe will require rich mixture setting maintain rpm prevent overheating OPS engine have found 0012 inches opti mum clearance giving reliable com petitive performance weathers conditions head clearance dividual engine must first established using depth gauge similar instrument may adjusted optimum inserting shims under head required Tuned-length exhaust pipe Due design two-stroke engine during cycle unburnt gases lost cylinder exhaust system tuned-length exhaust pipe simple reso nant device used improve perfor mance two-stroke engine pushing back cylinder some un burnt gases resonant frequency tuned pipe partly dependent its length must matched operat ing rpm engine ease reso nant length pipe normally regard ed terms length glow plug point widest diameter pipe decrease tuned length will raise operating rpm pipe crease tuned length will lower operating rpm pipe optimum length OPS unsilenced pipe OPS silenced pipe its rear can re moved has found 2325cm corresponds operating range between 22500 23500 ground rpm However reasons engine run below its best performance therefore suggest initial tuned length 24cm reducing optimum 025cm stages little power required Exhaust manifold standard OPS exhaust manifold has proved very satisfactory have therefore replaced component short mani fold machined solid aluminum bar joint between manifold tuned pipe best effected using silicon rubber tubing allowing gap 3mm expan sion movement between manifold pipe durable silicon rubber tubing currently available manufactured Micro Mold tubing will normally last six flights should replaced frequent intervals will prevent perforation exposed area hot exhaust gases addition above have available similar manifolds suited OS K&B engines continued * Paul Bowman refers finals semi-finals because number European countries including Great Britain modify FAL flying rules use FAI system selecting semifinalists Depending number heats flown competitor may drop worst score Typically scores counted would four out four four out five five out seven etc depending number heats flown organiz ers rank competitors eight top being chosen semi-final Two heats flown semi-finals fliers four fastest times qualify forthe final Places five through eight ranked semi-final times top four ranked final times top fliers tend regard heats almost practice semi-final final real competition Next month will have full report 84 Grand Prix races held Czechoslovakia conclusion Paul Bowmans article FAI racing See next month Bill Hager 706 Glen Haven Dr Conroe TX 77385 read about Model Aviation writing advertisers mention 140Model Aviation