Control Line SPEED Gene Hempel FAST has quite bit interest B Speed recently have asked Nick Sher would supply necessary infor mation write column about setting up Supertigre X-29 Since Nick now holds Open B Speed record has agreed fur nish information will done two parts because amount infor mation covered First disassemble X- 29 except bearings heat case oven approximately 3500 F facilitate removal bearings cae may have rap case piece wood bearings will fall out may find ben eficial wear some type heavy gloves fingers burned main bearing replaced Barden Series JOJH phenolic-cage thrust bearing Bardens pre cision bearing appropriate ap plication having upper speed limit 88600 rpm well both radial thrust load-bearing capability bearing fits shaft case no machining required crankshaft chrome-plated pol ished front bearing housing case enlarged until front bearing light slip-fit case no heat required get step-down diameter case front main bearing should enlarged polished ensure clearance shaft high rpms area should spected interference after first piped test run block Debun blend case main bypasses enter crankshaft area Clean parts thoroughly lacquer thinner dry have ultrasonic cleaner would work better Heat case assemble crank shaft spacer bearings case case still hot add prop driver bolt prop onto shaft give spin parts cool check smooth ness end-play end-play too loose 002-003 front bearing moving case Remove crankshaft shaft spacer behind front bearing Lightly lap down shaft spacer until proper end-play achieved crankshaft assembly complete oil 020 7h aI 238 070 BUTTON HEAD U-------- 525 ~f/4322B TAPPED HOLE II --I Ii 4746 BORE 6061 TG ALUM 125 AINCH BALL MILL 56 Model Aviation NICK Shars Supertigre X-29 holds AMA National CL B Speed Open record 20616 mph i stock No whats secret Nick shares system tuning us 2-pan series starting month Believe modifications relatively minor Nick Shers head modification Supertigre X-29 Originai head has comousuon cnamoer machined away becomes retainer new button-head insert aiso has giow plug threaded hole Sketch below gives dimensions info column Marvel Mystery Oil wrap up set aside next step remove rotor backplate Carefully examine backplate metal flashing around edges Use X-Acto knife No 11 blade care fully remove flashing face edges Obtain piece tempered glass about 12-14 square local glass shop will used lapping plate Place piece No 600 grit wet-or-dry sandpaper glass Pour small amount 3-in-I Oil sandpaper Sand circular direction face backplate until running surface smooth will have gray appearance after sanding Clean backplate liquid soap water Dip lacquer thinner set aside dry thoroughly rotor timing should Open 350 ABDC Close 650 ATDC Rotor timing can altered painting layout ink back surface scribing lines through venturi opening proper degree-wheel setting milling rotor dimension sharp corners should rounded except tim ing openigns deburred rotor should balanced finally chromeplated Polish both retaining pin rotor-mounting hole rotor should spin freely its pin Reassemble backplate rotor placing two strips 006 feeler gauge mate rial between rotor backplate Press rotor pin against rotor until have snug fit Now tighten rotor-pin set screw Use Locktite retaining screw silicone bathtub sealer rear backplate rotor pin terminates Now important partthe sleeve piston rework will need access lathe some machining sleeve stock piston relatively soft replaced machined hard sil icon aluminum Piston blanks obtained Performance Model Parts blanks machined Precision Metal Grind ing Addresses will given next column cylinder timing follows Exhaust 1760 Open ATDC Intake l301330 Open ATDC degree measurements made degree-wheel Timing cylinder can adjusted placing shim ring under flange sleeve machining bottom side sleeve flange see sketch exhaust port widened 0650 case exhaust opened cor respondingly small web main intakes removed intake ports contoured better gas flow skirts sleeve piston relieved facilitate better breathing de picted drawing After ports cylinder have cut deburred align piston cylinder bottom its stroke scribe relief-port outlines Remove piston material hand-held rotary cutting ~1 MACHINE FROM BOTTOM OF FLANGE X-29 STOCK CYLINDEI SIDE VIEW Cylinder-port timing adlusted either adding shims between flange top cylinder liner machining tad off undersurface shown Timing information given text stock ST piston replaced special lImited-production part tool piston now fitted rechromed honed sleeve P&G Metal Products sleeve finished 003 taper connecting rod deburred corners rounded polished wrist pin hole must thoroughly cleaned out gen erally quite bit machine shop residue trapped wrist pin groves wrist pin can flash-chromed desired Now have sleeve piston fitted will necessary machine new button-head First machine off head chamber stock head Bore out way through center head ap proximately 550 ID glow plug plug wrench clearnace part will used retainer button-head button-head machined piece 1 /s aluminum bar stock preferably 6061 T6 Drill way through glow plug hole using No 3 drill tap hole using /4-32 tap Check local hardware store tap combustion chamber made -in ball mill driven approximately 0125 deep produces squish band approximately 0 t46 side butILL Main pori-~ CO fl 1-our Boos-f parf ton should accommodate long-reach glow plug Set head clearance 006- 0065 consistent results employing No 4 GloBee plug No gaskets used ton lap-fitted cylinder head button should light slip-fit cyl inder develop problems check drawing clarification Machine button-head per external dimensions given drawing Now necessary machine work finished can start reassembling en gine very careful pull binds engine tightening bolts part causes engine bind remove part check what causing prob lem next installment will cover modi fication venturi run suctiontank setup plus information type fuel works best suction fuel system tuned pipe set-up Gene Hempel 301 N Yale Dr Garland iX 75042 rem ave web Ehatjs4.iiI wi d er-H-oP ______ 650 JL224 FRONT VIEW LINER contour rrnove PISTON 5IDE VIEW LI NER ModificatIons stock Supertigre cylinder liner follow age-old engine-tuning practice part detaIls given column February 1984 57
Edition: Model Aviation - 1984/02
Page Numbers: 56, 57
Control Line SPEED Gene Hempel FAST has quite bit interest B Speed recently have asked Nick Sher would supply necessary infor mation write column about setting up Supertigre X-29 Since Nick now holds Open B Speed record has agreed fur nish information will done two parts because amount infor mation covered First disassemble X- 29 except bearings heat case oven approximately 3500 F facilitate removal bearings cae may have rap case piece wood bearings will fall out may find ben eficial wear some type heavy gloves fingers burned main bearing replaced Barden Series JOJH phenolic-cage thrust bearing Bardens pre cision bearing appropriate ap plication having upper speed limit 88600 rpm well both radial thrust load-bearing capability bearing fits shaft case no machining required crankshaft chrome-plated pol ished front bearing housing case enlarged until front bearing light slip-fit case no heat required get step-down diameter case front main bearing should enlarged polished ensure clearance shaft high rpms area should spected interference after first piped test run block Debun blend case main bypasses enter crankshaft area Clean parts thoroughly lacquer thinner dry have ultrasonic cleaner would work better Heat case assemble crank shaft spacer bearings case case still hot add prop driver bolt prop onto shaft give spin parts cool check smooth ness end-play end-play too loose 002-003 front bearing moving case Remove crankshaft shaft spacer behind front bearing Lightly lap down shaft spacer until proper end-play achieved crankshaft assembly complete oil 020 7h aI 238 070 BUTTON HEAD U-------- 525 ~f/4322B TAPPED HOLE II --I Ii 4746 BORE 6061 TG ALUM 125 AINCH BALL MILL 56 Model Aviation NICK Shars Supertigre X-29 holds AMA National CL B Speed Open record 20616 mph i stock No whats secret Nick shares system tuning us 2-pan series starting month Believe modifications relatively minor Nick Shers head modification Supertigre X-29 Originai head has comousuon cnamoer machined away becomes retainer new button-head insert aiso has giow plug threaded hole Sketch below gives dimensions info column Marvel Mystery Oil wrap up set aside next step remove rotor backplate Carefully examine backplate metal flashing around edges Use X-Acto knife No 11 blade care fully remove flashing face edges Obtain piece tempered glass about 12-14 square local glass shop will used lapping plate Place piece No 600 grit wet-or-dry sandpaper glass Pour small amount 3-in-I Oil sandpaper Sand circular direction face backplate until running surface smooth will have gray appearance after sanding Clean backplate liquid soap water Dip lacquer thinner set aside dry thoroughly rotor timing should Open 350 ABDC Close 650 ATDC Rotor timing can altered painting layout ink back surface scribing lines through venturi opening proper degree-wheel setting milling rotor dimension sharp corners should rounded except tim ing openigns deburred rotor should balanced finally chromeplated Polish both retaining pin rotor-mounting hole rotor should spin freely its pin Reassemble backplate rotor placing two strips 006 feeler gauge mate rial between rotor backplate Press rotor pin against rotor until have snug fit Now tighten rotor-pin set screw Use Locktite retaining screw silicone bathtub sealer rear backplate rotor pin terminates Now important partthe sleeve piston rework will need access lathe some machining sleeve stock piston relatively soft replaced machined hard sil icon aluminum Piston blanks obtained Performance Model Parts blanks machined Precision Metal Grind ing Addresses will given next column cylinder timing follows Exhaust 1760 Open ATDC Intake l301330 Open ATDC degree measurements made degree-wheel Timing cylinder can adjusted placing shim ring under flange sleeve machining bottom side sleeve flange see sketch exhaust port widened 0650 case exhaust opened cor respondingly small web main intakes removed intake ports contoured better gas flow skirts sleeve piston relieved facilitate better breathing de picted drawing After ports cylinder have cut deburred align piston cylinder bottom its stroke scribe relief-port outlines Remove piston material hand-held rotary cutting ~1 MACHINE FROM BOTTOM OF FLANGE X-29 STOCK CYLINDEI SIDE VIEW Cylinder-port timing adlusted either adding shims between flange top cylinder liner machining tad off undersurface shown Timing information given text stock ST piston replaced special lImited-production part tool piston now fitted rechromed honed sleeve P&G Metal Products sleeve finished 003 taper connecting rod deburred corners rounded polished wrist pin hole must thoroughly cleaned out gen erally quite bit machine shop residue trapped wrist pin groves wrist pin can flash-chromed desired Now have sleeve piston fitted will necessary machine new button-head First machine off head chamber stock head Bore out way through center head ap proximately 550 ID glow plug plug wrench clearnace part will used retainer button-head button-head machined piece 1 /s aluminum bar stock preferably 6061 T6 Drill way through glow plug hole using No 3 drill tap hole using /4-32 tap Check local hardware store tap combustion chamber made -in ball mill driven approximately 0125 deep produces squish band approximately 0 t46 side butILL Main pori-~ CO fl 1-our Boos-f parf ton should accommodate long-reach glow plug Set head clearance 006- 0065 consistent results employing No 4 GloBee plug No gaskets used ton lap-fitted cylinder head button should light slip-fit cyl inder develop problems check drawing clarification Machine button-head per external dimensions given drawing Now necessary machine work finished can start reassembling en gine very careful pull binds engine tightening bolts part causes engine bind remove part check what causing prob lem next installment will cover modi fication venturi run suctiontank setup plus information type fuel works best suction fuel system tuned pipe set-up Gene Hempel 301 N Yale Dr Garland iX 75042 rem ave web Ehatjs4.iiI wi d er-H-oP ______ 650 JL224 FRONT VIEW LINER contour rrnove PISTON 5IDE VIEW LI NER ModificatIons stock Supertigre cylinder liner follow age-old engine-tuning practice part detaIls given column February 1984 57