# LS1 Engine for aircraft?

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#### Brian Clayton

##### Well-Known Member
I have yet to see someone say what exactly is the reliability problem with auto engines. PRSU aside.... Who has the pile of broken cranks, rods, blocks? I am sure Ross would agree, the hard parts in aircraft engines and auto engines are made the same, and the stock internals on either are nowhere as nice as aftermarket race parts. People keep bringing up the reliability issue.... what is it? What breaks that doesn't break in a "aircraft" engine?

#### rv6ejguy

##### Well-Known Member
I have yet to see someone say what exactly is the reliability problem with auto engines. PRSU aside.... Who has the pile of broken cranks, rods, blocks? I am sure Ross would agree, the hard parts in aircraft engines and auto engines are made the same, and the stock internals on either are nowhere as nice as aftermarket race parts. People keep bringing up the reliability issue.... what is it? What breaks that doesn't break in a "aircraft" engine?
Couldn't have said it better. People against auto conversions usually have a "feeling" that auto engines won't run at WOT 3000-4500 rpm for a long time but in 10 years on forums, nobody has ever shown me a lot a broken parts to back up their feelings. In fact, as I've said so often, the OEMs test every new design far in excess of what the FAA requires for certified engines. Typical modern day endurance testing involves between 200 and 1200 hours at WOT, torque peak to power peak rpm on a single example and they would run dozens of examples similarly to validate the design prior to production release.

Does anyone here really think running an LSX at 2500-2800 rpm WOT is going to break it or wear it out prematurely? GM did a test way back on the LS1- 420 hours I believe at FULL rated power. Everything within limits upon disassembly.

#### Brian Clayton

##### Well-Known Member
Look at generators and big water pumps driven with automotive engines and small engines (briggs type). Hours and hours and hours at full load. Some are even made to change the oil without shutting the engine down. Want a direct drive? Fine, turn it upside down and put a dry sump pump on it. Thrust bearing issues? Pick a bearing and some basic machine work and there you go. Looks to me like dedicated aircraft engines in aircraft enviroments fail more often than automotive engines in automotive enviroments (mechanical failure from stress not abuse). When is the last time you saw a cylinder and head come flying off of a v style or inline automotive engine? Or saw a cracked flywheel flange? If LS engines has the same failure rate as a Rotax, people would walk instead of drive. Yes, I understand the stresses of a WOT engine are different than the subdued driving habits of people, but I don't believe it is that much different. I would hazard a guess to say that the constant up and down revs of a engine coupled to a transmission are far greater stresses than WOT stresses of a prop at a fairly constant rpm. Ross has been flying his "car engine" for how long? How many hours? And no offense intended, but it probably was not worth a crap as a car engine.

E

#### ekimneirbo

##### Guest
Look at generators and big water pumps driven with automotive engines and small engines (briggs type). Hours and hours and hours at full load. Some are even made to change the oil without shutting the engine down. Want a direct drive? Fine, turn it upside down and put a dry sump pump on it. Thrust bearing issues? Pick a bearing and some basic machine work and there you go. Looks to me like dedicated aircraft engines in aircraft enviroments fail more often than automotive engines in automotive enviroments (mechanical failure from stress not abuse). When is the last time you saw a cylinder and head come flying off of a v style or inline automotive engine? Or saw a cracked flywheel flange? If LS engines has the same failure rate as a Rotax, people would walk instead of drive. Yes, I understand the stresses of a WOT engine are different than the subdued driving habits of people, but I don't believe it is that much different. I would hazard a guess to say that the constant up and down revs of a engine coupled to a transmission are far greater stresses than WOT stresses of a prop at a fairly constant rpm. Ross has been flying his "car engine" for how long? How many hours? And no offense intended, but it probably was not worth a crap as a car engine.

RV6 Guy Quote "Couldn't have said it better. People against auto conversions usually have a "feeling" that auto engines won't run at WOT 3000-4500 rpm for a long time but in 10 years on forums, nobody has ever shown me a lot a broken parts to back up their feelings. In fact, as I've said so often, the OEMs test every new design far in excess of what the FAA requires for certified engines. Typical modern day endurance testing involves between 200 and 1200 hours at WOT, torque peak to power peak rpm on a single example and they would run dozens of examples similarly to validate the design prior to production release.

Does anyone here really think running an LSX at 2500-2800 rpm WOT is going to break it or wear it out prematurely? GM did a test way back on the LS1- 420 hours I believe at FULL rated power. Everything within limits upon disassembly.

I added the quote from RV6Guy into this reply because I agree with both him and Brian. The thing about WOT is that its a subjective term. On certified Lyc/Cons 2700 rpm is often referred to as WOT.........but it really isn't. These engines are capable of spinning at higher rpms, its just that the propellors they are turning limit the rpm because of tip speed. I'm sure I'm not telling Brian/RV6 anything they don't already know, but others seem to refer to the reccommended rpm of the propellor as being the maximum WOT of the engine. Its incorrect to say that these engines won't turn higher rpms and do so for an extended period of time. There are several different certified engines that do turn higher rpms and utilize a reduction gear.
Any engine can have its maximum WOT established by the engine manufacturer and then modified by an individual. GM makes some big block engines to work in pumping situations that have cams designed for low rpm only useage. Take this engine apart and put a different cam in it and the required valves and valve springs and you can change its operating rpm range. So any engine can be purpose built to operate in a given range. The sweet thing about most automotive engines is that they have been engineered to thrive in spite of poor treatment and maintainance and still run at higher rpms than a certified engine can even dream of. The massive pistons and power pulses won't allow the GA airplane engines to run that fast, but they will run faster than 2700 rpms.
On another thread in the general automotive section, the venerable Ron Watanaja mentioned that basic engine to basic engine, the reliability of automotive engines exceeds aircraft engines. (I don't want to put words in his mouth, so you should read the thread and see if you agree with my understanding of what he said) The problem usually arises in the method of adapting the auto engine to the propellor.

#### Toobuilder

##### Well-Known Member
HBA Supporter
Log Member
Agree with the general gist of the above thread, but to make a small correction: WOT means "wide open throttle" - a reference to the angle of throttle blade opening or manifold pressure. This is unrelated to "redline" which is most often a reference to RPM. Many aircraft engines are at "WOT" from the beginning of the takeoff roll, through the flight and until the descent phase- often with substantially less than redline RPM for most of that time.

One can just as easily be at "WOT" at redline or some substantially less RPM. Additionally, you can also be at WOT and still well under 100% power.

#### Brian Clayton

##### Well-Known Member
My idea of WOT and probably Russ too, is 100 percent open throttle with the engine loaded as hard as it will pull at a given rpm. 100% power would be subjective to the peak power of the engine. I am sure that if you re-cam a 0-200 and spin it up to wherever the heads quit, it would make quite a bit more than 100 hp, thus moving 100% power to a different rpm versus whatever they are stock. If you change a LS1 to run at say 2500, and load it 100 percent there, then the stresses would be less than higher rpms. Then you could start hacking down the parts to lose weight (like aircraft engines) because the stresses are less. I can say one thing from my experience with race engines, high rpm kills much, much faster than high horsepower or high loadings. I don't see why a LS1 engine could not be lightened up a good bit, because of lower stress. Heck, race cranks can be made down 30 lbs or so lighter than stock cranks....made for engines that make 2-3 times stock power at 2000-3000 more rpm than stock redline.

#### rv6ejguy

##### Well-Known Member
I use the term WOT a lot because so many lay people think that since auto engines spend most of their lives at part throttle cruise that they will wear out or blow up if you run long periods of full throttle. If at WOT, then hp developed just depends on rpm and altitude/ MAP. In geared auto conversions we normally only rev to about 2/3rds to 3/4 of peak power or redline rpm as the case may be so in stock form we have derated them to about 65-75% power and the mechanical stress levels are far below any critical levels. Many good auto engine designs can produce 4-5 times the stock hp output when turbocharged using the stock crank, rods, block, head etc. (I've done it) That is how big some of the design margins are. You can't say that about any certified engine designs to my knowledge.

We do need to manage piston and valve temperatures for longevity. You can either run rich as the OEMs do at high power levels or replace the stock parts with forged and stainless parts respectively. Many modern designs already have under piston oil jets to cool them and excellent valve and seat materials. These engines don't need any changes for aviation use in most cases.

I agree with Brian about rpm, it is the main killer of longevity. This is why I had such great success with small turbocharged road racing engines vs. larger displacement atmo competitors. We only had to rev to 6500-7000 rpm to beat them with 1/2 to 2/3rds of the displacement while they had to flog their engines at 8500 to try to keep up. They often broke valvetrain stuff and rods/ cranks. My stuff never broke.

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#### ekimneirbo

##### Guest
Agree with the general gist of the above thread, but to make a small correction: WOT means "wide open throttle" - a reference to the angle of throttle blade opening or manifold pressure. This is unrelated to "redline" which is most often a reference to RPM. Many aircraft engines are at "WOT" from the beginning of the takeoff roll, through the flight and until the descent phase- often with substantially less than redline RPM for most of that time.

One can just as easily be at "WOT" at redline or some substantially less RPM. Additionally, you can also be at WOT and still well under 100% power.
I overlooked that point in my comments and you are correct that WOT is when the throttle blade is parallel to the intake tract opening. I don't think most certified engines are exactly at WOT when they hit the redline on the tach. I think there is still some room for movement which will take the engines above the 2700 rpm point, but I may be wrong about that. I would think that it would be hard to get all engines of a same type to run at exactly 2700 rpms when the throttle plate is WOT. To me it would seem that there has to be some leeway in the combination of parts used to attain a given rpm setting. Not all jets or intake tracts or carbs are going to function exactly the same.......so 2700 rpms may occur at less than WOT due to jetting, intake variations, filters, and even the density of the atmosphere.

#### rv6ejguy

##### Well-Known Member
I overlooked that point in my comments and you are correct that WOT is when the throttle blade is parallel to the intake tract opening. I don't think most certified engines are exactly at WOT when they hit the redline on the tach. I think there is still some room for movement which will take the engines above the 2700 rpm point, but I may be wrong about that. I would think that it would be hard to get all engines of a same type to run at exactly 2700 rpms when the throttle plate is WOT. To me it would seem that there has to be some leeway in the combination of parts used to attain a given rpm setting. Not all jets or intake tracts or carbs are going to function exactly the same.......so 2700 rpms may occur at less than WOT due to jetting, intake variations, filters, and even the density of the atmosphere.
We often fly at WOT for lower pumping losses at high altitudes. 8000 to 8500 feet gives about 75% power. Depends on prop rpm. With a CS prop, you have more choices in power settings via set rpm.

#### Brian Clayton

##### Well-Known Member
sure....take the prop off and it will hit 2700 at 10 percent throttle.

#### Toobuilder

##### Well-Known Member
HBA Supporter
Log Member
Right. With a constant speed prop, you set the RPM and forget it.

#### ekimneirbo

##### Banned
Some reference info for LS engines

 Gen III & Gen IV Small Blocks Part Number Description Liters CID HP TQ Bore Stroke 19165628 LS327/327 5.3 327 327 347 3.780" 3.622" 17801267 LS1 5.7 346 350 365 3.898" 3.622" 17801268 LS6 5.7 346 405 395 3.898" 3.622" 19156262 LQ9 6.0 364 345 380 4.000" 3.622" *19165484 LS2 6.0 364 400 400 4.000" 3.622" *17802134 LS364/440 6.0 364 440 404 4.000" 3.622" 12611022 L99 6.2 376 430 424 4.065 3.622" 19171224 LS376/485 6.2 376 485 475 4.065" 3.622" 19171225 LS376/515 6.2 376 515 469 4.065" 3.622" 19201992 LS3 6.2 376 430 424 4.065" 3.622" 19211978 LSA 6.2 376 556 551 4.065" 3.622" 19201990 LS9 6.2 376 638 604 4.065" 3.622" 19171821 CT525 6.2 376 525 471 4.065" 3.622" 19165058 LS7 7.0 427 505 470 4.125" 4.000" * Discontinued
 LS Compatibility - Heads vs. Intakes Intakes Heads Engine Part # Manifold Port Type 12559855 LS1 12564824 LS6/LS2 12562319 LQ9 88958665 CNC LS6 88958622 CNC LS6 12582713 L76/L92 12615879 LS3 88958698 CNC L92 LS1/LS6 88894339 EFI Cathedral Yes Yes Yes Yes Yes No No No LS2/LQ4 88958675 4-bbl Cathedral Yes Yes Yes Yes Yes No No No LQ4/LQ9 N/A EFI Cathedral Yes Yes Yes Yes Yes No No No L76 12590123 EFI L92 No No No No No Yes Yes Yes LS3 12610434 EFI L92 No No No No No Yes Yes Yes L76/L92/LS3 25534416 4-bbl w/inj L92 No No No No No Yes Yes Yes L76/L92/LS3 25534401 4-bbl L92 No No No No No Yes Yes Yes L92/LS3 19166952 LSX 4bbl L92 No No No No No Yes Yes Yes L92/LS3 19172322 LSX 4bbl L92 No No No No No Yes Yes Yes LS7 '05-'08 12568976 EFI LS7 No No No No No No No No LS7 '09 12610435 EFI LS7 No No No No No No No No LS7 25534413 4-bbl w/inj LS7 No No No No No No No No LS7 25534394 4-bbl LS7 No No No No No No No No LSX 454 19166948 LSX 4bbl LS7 No No No No No No No No 19166950 LSX 4bbl LSX-CT No No No No No No No No 19166954 LSX 4bbl LSX-DR No No No No No No No No No=not compatable Yes=direct compatability Intakes Heads Engine Part # Manifold Port Type 19201807 LSX-L92 19201805 LSX-LS3 19213963 LSX-LS9 12578450 CNC LS7 19201806 LSX-LS7 19166981 LSX-CT 19166979 LSX-DR 12480090 C5R LS1/LS6 88894339 EFI Cathedral No No No No No No No No LS2/LQ4 88958675 4-bbl Cathedral No No No No No No No No LQ4/LQ9 N/A EFI Cathedral Yes Yes Yes No No No No No L76 12590123 EFI L92 Yes Yes Yes No No No No No LS3 12610434 EFI L92 Yes Yes Yes No No No No No L76/L92/LS3 25534416 4-bbl w/inj L92 Yes Yes Yes No No No No No L76/L92/LS3 25534401 4-bbl L92 Yes Yes Yes No No No No No L92/LS3 19166952 LSX 4bbl L92 Yes Yes Yes No No No No No L92/LS3 19172322 LSX 4bbl L92 Yes Yes Yes No No No No No LS7 '05-'08 12568976 EFI LS7 No No No Yes Yes No No No LS7 '09 12610435 EFI LS7 No No No Yes Yes No No No LS7 25534413 4-bbl w/inj LS7 No No No Yes Yes No No No LS7 25534394 4-bbl LS7 No No No Yes Yes No No No LSX 454 19166948 LSX 4bbl LS7 No No No Yes Yes No No No 19166950 LSX 4bbl LSX-CT No No No No No Yes Yes No 19166954 LSX 4bbl LSX-DR No No No No No Yes Yes No No=not compatable Yes=direct compatability
 LS Compatability - Heads vs. Blocks Blocks Heads Engine Part # Bore Size 12559855 LS1 12564824 LS6/LS2 12562319 LQ9 88958665 CNC LS6 88958622 CNC LS6 12582713 L76/L92 12598594 LS3 88958698 CNC L92 LS1/LS6 12561166 3.89" Yes Yes Yes Yes Yes No No No LQ4/LQ9 12572808 4.00" Yes Yes Yes Yes Yes Yes Yes Yes LS2/L76 12568950 4.00" Yes Yes Yes Yes Yes Yes Yes Yes L92/LS3 12584727 4.06" Yes Yes Yes Yes Yes Yes Yes Yes LSA/LS9 4.06" Yes Yes Yes Yes Yes Yes Yes Yes LS7 17802854 4.125" Yes Yes Yes Yes Yes Yes Yes Yes LS7* 25534427 4.125" Yes Yes Yes Yes Yes Yes Yes Yes C5R 12480030 4.12"-4.16" Yes Yes Yes Yes Yes Yes Yes Yes LSX S/B 19213964 3.89" Yes Yes Yes Yes Yes * * * LSX 19166454 3.99"-4.25" * * * * * * * * LSX TD 19166097 3.99"-4.25" * * * * * * * * No=not compatable Yes=direct compatability *=4.00 min Bore **=4.125" min Bore ***=4.100" min Bore Blocks Heads Engine Part # Bore Size 19201807 LSX-L92 19201805 LSX-LS3 19213963 LSX-LS9 12578450 CNC LS7 19201806 LSX-LS7 19166981 LSX-CT 19166979 LSX-DR 12480090 C5R LS1/LS6 12561166 3.89" Yes No No No No No No No LQ4/LQ9 12572808 4.00" Yes Yes Yes No No No No No LS2/L76 12568950 4.00" Yes Yes Yes No No No No No L92/LS3 12584727 4.06" Yes Yes Yes No No No No No LSA/LS9 4.06" Yes Yes Yes No No No No No LS7 17802854 4.125" Yes Yes Yes Yes Yes Yes Yes Yes LS7* 25534427 4.125" Yes Yes Yes Yes Yes Yes Yes Yes C5R 12480030 4.12"-4.16" Yes Yes Yes Yes Yes Yes Yes Yes LSX S/B 19213964 3.89" ** ** ** ** *** ** ** ** LSX 19166454 3.99"-4.25" ** ** ** ** *** ** ** ** LSX TD 19166097 3.99"-4.25" ** ** ** ** *** ** ** ** No=not compatable Yes=direct compatability *=4.00 min Bore **=4.125" min Bore ***=4.100" min Bore
 LS Series Blocks Origin Part # Material Deck Height Bore Main Bolt Cap Material Crank Jrnl Dia Oiling Rr Main Seal Max Stroke Max HP Usage LS1/LS6 12561166 Alum 9.240 3.89" 6 Iron Std LS 2.56 Wet 1 Pc 4.00" 450 Street LS2 12568950 Alum 9.240 4.00" 6 Iron Std LS 2.56 Wet 1 Pc 4.00" 450 Street L92/LS3 12584727 Alum 9.240 4.065" 6 Iron Std LS 2.56 Wet 1 Pc 4.00" 525 Street LS7 17802854 Alum 9.240 4.125" 6 PM Std LS 2.56 Dry 1 Pc 4.10" 550 Street LS7 25534427 Alum 9.240 4.125" 6 PM Std LS 2.56 Dry 1 Pc 4.10" 550 Street C5R 12480030 Alum 9.240 4.117"-4.160" 6 8620 Steel Std LS 2.56 Wet 1 Pc 4.10" 900 Pro LQ9 12572808 Iron 9.240 4.00" 6 Iron Std LS 2.56 Wet 1 Pc 4.00" 500 Street LSX 19166454 Iron 9.260 3.99"-4.250" 6 1045 Steel Std LS 2.56 Wet 1 Pc 4.25" 1500+ Street/Pro LSX 19166097 Iron 9.700 3.99"-4.250" 6 1045 Steel Std LS 2.56 Wet 1 Pc 4.50" 1500+ Street/Pro
 LS Series Heads Part # Origin Material Port Size Valve Angle Chamber CC's Int Valves Exh Valves Port Type Rocker Stud Notes 12564825 Bare LS2 & LS6 Alum 210 15 degree 64.5 2.00 1.55 Cathedral Bolt Bare LS2/LS6 12564824 Stock LS6 Alum 210 15 degree 64.5 2.00 1.55 Cathedral Bolt Hollow/Sodium filled Valves 12576063 Stock LS2 Alum 210 15 degree 64.5 2.00 1.55 Cathedral Bolt Solid stem valves 88958622 CNC LS6 Alum 250 15 degree 61.9 2.00 1.55 Cathedral Bolt 11.2 compression 88958665 CNC LS6 Alum 250 15 degree 65 2.00 1.55 Cathedral Bolt 10.5 compression 88958765 CNC LS2 Alum 250 15 degree 64.5 2.00 1.55 Cathedral Bolt Solid stem valves 12582714 Bare L76/L92 Alum 260 15 degree 70 2.16 1.59 L92 Bolt Solid stem valves 12582713 Stock L76/L92 Alum 260 15 degree 70 2.16 1.59 L92 Bolt Solid stem valves 88958698 CNC L76/L92 Alum 279 15 degree 68 2.16 1.59 L92 Bolt Solid stem valves 12598594 Stock LS3 Alum 260 15 degree 70 2.16 1.59 L92 Bolt Hollow/Sodium filled Valves 12578450 Bare LS7 Alum 270 12 degree 70 2.20 1.61 LS7 Bolt Bare LS7 12578449 Stock LS7 Alum 270 12 degree 70 2.20 1.61 LS7 Bolt Titanium/sodium filled valves 25534428 As-cast LS7 Alum - 12 degree 66 2.20 1.61 LS7 Bolt Titanium/sodium filled valves 12480005 * C5R 1st design Alum 210 11 degree 38 2.18 1.63 C5R Shaft As cast-no seats, guides * 12480090 C5R 2nd design Alum 210 11 degree 30 2.18 1.63 C5R Shaft As cast-no seats, guides 19201807 LSX-L92 Small Bore Alum 260 15 degree 70 2.00 1.55 L92 Bolt Hollow/Sodium filled Valves 19201805 LSX-LS3 Alum 260 15 degree 70 2.16 1.59 L92 Bolt Hollow/Sodium filled Valves 19201806` LSX-LS7 Alum 270 12 degree 70 2.20 1.61 LS7 Bolt Hollow/Sodium filled Valves 19166981 LSX-CT Alum 302 11 degree 45 2.20 1.61 LSX-CT/DR Shaft CNC machined bare head 19166979 LSX-DR Alum 313 11 degree 50 2.25-2.28 1.6-1.65 LSX-CT/DR Shaft CNC machined bare head *Discontinued

 LS Series Head Gaskets & Bolts Part # Engine Thickness Max Bore Description 12498544 LS1 2002-2004 .047" 3.92 Standard LS Bolt Pattern 12589226 LS1 & LS6 .051" 3.92" Standard LS Bolt Pattern 12589227 LS2 .051" 4.02" Standard LS Bolt Pattern 12610046 LS3 & L92 .051" 4.080" Standard LS Bolt Pattern 12582179 LS7 .051" 4.140" Standard LS Bolt Pattern 19170418 LSX .051" 4.100" Standard LS & 6-Bolt Pattern Blocks & Heads 19170419 LSX .051" 4.200" Standard LS & 6-Bolt Pattern Blocks & Heads 19170420 LSX .051" 4.250" Standard LS & 6-Bolt Pattern Blocks & Heads 17800568 1/2004 & up LS Engines Includes 15 bolts 5mm shorter than 1st Design 12498545 97-1/04 LS Engines Includes 15 bolts

 LS Series Camshafts Part # Description Duration @ .050" lift Max Lift (In) (1.7 rocker) Lobe Seperation Technical Notes 12565308 2002-2004 LS6 Cam I:204 E:218 I:550 E:550 117.5 Cam requires valve spring P/N 12586484 12560950 2001 LS6 Cam I:207 E:217 I:525 E:525 116 Cam requires valve spring P/N 12586484 12480110 ASA Cam I:226 E:236 I:525 E:525 110 Cam requires valve spring P/N 12586484 "ASA" cam for off-highway use 12480033 Hot Cam Kit I:219 E:228 I:525 E:525 112 Kit includes 16 LS6 Valve Springs P/N 12565117 and retainers 88958733 LS Hot Cam I:219 E:228 I:525 E:525 112 Cam only for Hot Cam Kit 12480033 19166972 LSX-454 Cam I:236 E:246 I:600 E:600 110 Max lift with 1.8 rockers .635/.635 88958606 Showroom Stock cam I:239 E:251 I:570 E:570 106.5 Showroom Stock racing design, requires hollow intake valves #12565311, hollow exhaust valves #12565312, valve springs #12586484, and aftermarket notched pistons or machined stock pistons 12571251 LS7 I:211 E:230 (1.8 Rocker) I:591 E:591 121 Stock LS7 camshaft 12561721 LS1 2001-2004 LQ9 2002-2006 I:196 E:201 I:467 E:479 116 Stock cam for 2002-2006 LQ9 and 2001-2004 LS1 88958722 LS Stage 2 Cam I:227 E:239 (1.7 Rocker) I:551 E:551 108 Max lift with 1.8 rockers .583/.583 88958723 LS Stage 3 Cam I:233 E:276 (1.7 Rocker) I:595 E:595 107 Max lift with 1.8 rockers .630/.630

 LS Series Pistons Part # Engine Size Bore Size Oversize Rod Length Pin Type Comp Ratio With Chamber Description 88984245 5.7L 3.898" - 6.098" Pressed - 65.00 Hypereutectic LS1 & LS6 replacement 88984246 5.7L 3.898" +.010" 6.098" Pressed - 65.00 Hypereutectic LS1 & LS6 replacement 89017478 6.0L 4.000" - 6.098" Floated 10.90 65.00 Hypereutectic LS2 & LQ9 replacement 89017479 6.0L 4.000" +.020" 6.098" Floated 10.90 65.00 Hypereutectic LS2 & LQ9 replacement 12602624 7.0L 4.125' - 6.067" Floated 11.00 70.00 Hypereutectic LS7 replacement includes Titanium Rod 89018171 7.0L 4.125" +.020" 6.067" Floated 11.00 70.00 Hypereutectic LS7 replacement 19166957 LSX376 4.065" 6.098" Flat - 4032 Forged Aluminum -Piston comes w/ rings 19166958 LSX454 4.185" LSX rod 0.866 Dished - 4032 Forged Aluminum -

 LS Rings Part # Bore Size Oversize Ring Thickness Description 12499234 3.898" - 1.5, 1.5, 2.5mm Set of 8 ring packs, standard size for LS1 & LS6 12499236 4.000" - 1.5, 1.5, 2.5mm Set of 8 ring packs, standard size for 1999-2005 LQ4 & LQ9 12499235 3.780" - 1.5, 1.5, 2.5mm Set of 8 ring packs, standard size for 1999-2005 5.3L 89017484 4.000" - 1.5, 1.5, 2.5mm Production ring pack for 2005-2006 LS2 & 2006 L76 88894243 4.000" - 1.5, 1.5, 2.5mm Production ring pack for 2005-2006 LQ9 89017776 4.125" - 1.2, 1.2, 2.0mm Production ring pack for 2006 LS7 89017777 4.125" +.020" 1.2, 1.2, 2.0mm Oversize LS7 ring pack

 LS Series Push Rods Part # Engine Material Diameter Length Description 12593344 LS1, LS2, LS3, LS6 & L92 1010 Steel 5/16" 7.325" Production pushrod 12593344 LS7 1010 Steel 3/8" 7.750" Production pushrod

 LS Series Valves Part # Engine Position Valve Size Stem Dia 12565311 LS6 Intake 2.00" 8mm Hollow Stem 12563063 LS2 Intake 2.00" 8mm Solid Stem 12590773 L76 & L92 Intake 2.165" 8mm Solid Stem 12605223 LSA Intake 2.165" 8mm Solid Stem 12569427 LS3 Intake 2.165" 8mm Hollow Stem 12605524 LS9 Intake 2.165" 8mm Titanium 12591644 LS7 Intake 2.20" 8mm Titanium 12565312 LS6 Exhaust 1.50" 8mm Sodium Filled 12563064 LS2 Exhaust 1.50" 8mm Solid Stem 12582719 L76, L92 & LS3 Exhaust 1.59" 8mm Solid Stem 12605525 LS9 Exhaust 1.59" 8mm Sodium Filled 12578455 LS7 Exhaust 1.61" 8mm Sodium Filled 17801930 LS2 & LS6 (4)Intake & (4)Exhaust I -2.00" E-1.50" 8mm LS6 Hollow & Sodium Valves

 LS Series Valve Springs Part # Engine Style Installed Height Open Pressure Max Lift Description 12586484 Standard LS2, LS6 & LS6 Beehive Style 1.800" Installed @ 90# pressure 1.250" @ 295 # pressure .570" Individual 12499224 Standard LS2, LS6 & LS6 Beehive Style 1.800" Installed @ 90# pressure 1.250" @ 295 # pressure .570" Set of 16 P/N 12586484 12589774 Standard L76/L92 Springs Beehive Style 1.800" Installed @ 90# pressure 1.300" @ 264# pressure .530" 12578457 LS7 Beehive Style 1.960" Installed @ 101# pressure 1.368" @ 310# pressure .600"

 LS Timing Components Part # Engine Part Oil Pump System Description 12588670 LS2 Timing Chain Dampner Standard Will not Fil LS1 & LS6 fitted with P/N 88958607 12581276 LS7 Timing Chain Dampner LS7 2-stage 1.1mm thinner than 12588670 12576407 LS1, LS2 & LS6 1X Camshaft Gear - 3-bolt design; uses (3) bolts P/N 12556127 12586481 LS1, LS2 & LS6 4X Camshaft Gear - 3-bolt design; uses (3) bolts P/N 12556127 12585994 L92 - Combination Cam gear and VVT activator 4X Camshaft Gear - 1-bolt design; use P/N 12588151 12556582 All Non LS7 Crankshaft Gear Standard Works with 12576407 and 12586481 cam sprockets 12581278 LS7 Crankshaft Gear LS7 2-stage Works with 12576407 and 12586481 cam sprockets 12586482 All LS Timing Chain - Fits all LS 1997-2008 12585997 L92 & LS3 Timing Chain Tensioner - Includes retainer and bolts 12556127 LS1,LS2,LS6 & LS7 Camshaft Gear bolts - For use with 3-bolt (non V.V.T.) cams 12588151 L92 Camshaft Gear bolts - Combination bolt and valve for variable valve timing - use with 12585994 Camshaft Gear

 LS Crankshafts Part # Application Material Reluctor Wheel Stroke Description 89017522 97-04 LS1/LS6 & 2005 LS2 Nodular Cast 24X 3.622" Balanced for 3.898" bore engines 12588612 2006 and up LS2 Nodular Cast 58X 3.622" Balanced for 4.00" bore engines 12568820 LS7 Forged Steel 58X 4.00" Rebalancing required if LS7 rods and pistons are not used. 2-stage Oil pump 19171619 LS Forged Steel 58X 4.00" Rebalancing required if LS7 rods and pistons are not used. Standard wet sump Oil pump 12559353 1997-2005 - 24X - 1997-2005 Reluctor Wheel 12586768 2006 and up - 58X - 2006 and newer Reluctor Wheel 89060436 All LS Rear Main Seal - - Rear Main Seal for all LS engines
 LSX Crankshafts Part # Note Material Reluctor Wheel Stroke Description 19170388 8-bolt flywheel or flexplate required 4340 premium steel 58X 3.622" Reguires Balancing 19170389 8-bolt flywheel or flexplate required 4340 premium steel 58X 3.750" Reguires Balancing 19170390 8-bolt flywheel or flexplate required 4340 premium steel 58X 4.00" Reguires Balancing 19170391 8-bolt flywheel or flexplate required 4340 premium steel 58X 4.125" Reguires Balancing

 LS Connecting Rods Part # Application Material Piston Fit Length Description 12568734 1997-2004 LS1 & LS6 PM Press 6.098" Sold Individually 12617570 2005-2008 LS2 & LS3 PM Float - Bronze Bushing 6.098" Sold Individually 12586258 LS7 Titanium Float - Bronze Bushing 6.067" Sold Individually 19166964 LSX I-beam 4340 Forged Steel Float - Bronze Bushing 6.000" Set of 8, weight matched - NOT compatible with production pistons-for use with LSX Pistons INCLUDES 7/16" 12-point SAE 8740 rod bolts 19166965 LSX I-beam 4340 Forged Steel Float - Bronze Bushing 6.100" Set of 8, weight matched - NOT compatible with production pistons-for use with LSX Pistons INCLUDES 7/16" 12-point SAE 8740 rod bolts 19166966 LSX I-beam 4340 Forged Steel Float - Bronze Bushing 6.125" Set of 8, weight matched - NOT compatible with production pistons-for use with LSX Pistons INCLUDES 7/16" 12-point SAE 8740 rod bolts 19166967 LSX I-beam 4340 Forged Steel Float - Bronze Bushing 6.150" Set of 8, weight matched - NOT compatible with production pistons-for use with LSX Pistons INCLUDES 7/16" 12-point SAE 8740 rod bolts 19166968 LSX I-beam 4340 Forged Steel Float - Bronze Bushing 6.200" Set of 8, weight matched - NOT compatible with production pistons-for use with LSX Pistons INCLUDES 7/16" 12-point SAE 8740 rod bolts 11600158 Rod Bolt LS6 - - - Recommended in Gen III performance engines-Bolts have greater strength than pre-2000 rod bolts- 1 per package 11609825 Rod bolt LS7 - - - Required for LS7 builds-bolts are stretch to yield and can not be reused - 1 bolt per package 89017573 Rod Bearing All except LS7/LS9 - - - Connecting Rod Bearing - (1) per rod required 89017811 Rod Bearing LS7/LS9 - - - Connecting Rod Bearing - (1) per rod required

#### HoneyMoneyToo

##### Member
Fist post and joined just to comment on this. I know this is an older thread but ... When my dad died in 01 I got his brand new off the lot 5.3 vortec 327ish cubic inch (LS based) reg cab silverado 2wd. I was 14 at the time and my mother drove me everywhere in it until I was 15 -16. I am from a small town with LOTS of dirt roads so I Pounded and Pounded on that engine. I raced people, I did donuts, all kinda stuff a teenager would do . I even ended up putting a 125hp shot of NOS on it for when I went to the drag strip. That motor NEVER let me down. My water pump went out once and a fuel pump but other than that no problems from engine. I busted 2 transmissions with it and had 160,000 ish miles on it before I took it out to put another LS based motor 6.0 vortec (LS based, LQ9) around 2011. If that motor can take all that I put it through all those years and WOT pulls and still run, its got my vote. With that said If you took an almunium 427 or 408 (6.0 bored .30 over with 4" stroke) used top quality parts (forged, with ARP fastners, ect) set up for low end TQ and HP "derated" it and only ran at 2500-3000 RPM for the redline like other plane engines. Whats the difference besides air cooled, dual spark plugs ect? Just a LOT cheaper you can set up redundant sensors and such (to an extent) ... No matter what they are all man made and are all prone to break from defects or what not, invest in a BRS parachute

#### ekimneirbo

##### Banned
Fist post and joined just to comment on this. I know this is an older thread but ... When my dad died in 01 I got his brand new off the lot 5.3 vortec 327ish cubic inch (LS based) reg cab silverado 2wd. I was 14 at the time and my mother drove me everywhere in it until I was 15 -16. I am from a small town with LOTS of dirt roads so I Pounded and Pounded on that engine. I raced people, I did donuts, all kinda stuff a teenager would do . I even ended up putting a 125hp shot of NOS on it for when I went to the drag strip. That motor NEVER let me down. My water pump went out once and a fuel pump but other than that no problems from engine. I busted 2 transmissions with it and had 160,000 ish miles on it before I took it out to put another LS based motor 6.0 vortec (LS based, LQ9) around 2011. If that motor can take all that I put it through all those years and WOT pulls and still run, its got my vote. With that said If you took an almunium 427 or 408 (6.0 bored .30 over with 4" stroke) used top quality parts (forged, with ARP fastners, ect) set up for low end TQ and HP "derated" it and only ran at 2500-3000 RPM for the redline like other plane engines. Whats the difference besides air cooled, dual spark plugs ect? Just a LOT cheaper you can set up redundant sensors and such (to an extent) ... No matter what they are all man made and are all prone to break from defects or what not, invest in a BRS parachute
Good first post...I like the way you think.

#### pistoncan

##### Well-Known Member
There are several companies manufacturing items to use an LS series engine. Most of them use a reduction drive. This seems to be one of those situations where everyone follows the same lead and assumes it must be the only/best way. I'm not saying its wrong, but to my way of thinking, it may not be the best way...at least in my set of circumstances.

If you use a reduction drive, what do you gain?

1. You gain the ability to run the engine at a higher RPM and create more HP
for takeoff. You will also need more HP to carry the weight.
2. You can run the engine at a somewhat higher RPM level and increase cruising speed. This along with the added weight will reduce the distance you can travel before landing, and may be greater than the airplanes maximum speed. You'll get to the gas pump quicker....
3. You increase the cost and complexity of building the airplane and reduce the TBO. You place added strain on the engine components at higher rpms.
4. You may have to compensate to get your weight and balance to offset the added weight. You lose cargo capacity, and gliding distance, increase stall speed.

My opinion (and its just that...an opinion) is that trying to mimic an airplane engine is the best way to go. If 160/200 hp is sufficient to fly the airplane, then what good is having 300 hp? When cruising, you will probably only require a 100HP or so, and if you want to fly at top speed, figure how many HP you need and shoot for ...say 20 more than that and direct drive.

How do you get there? My opinion again...cubic inches. Everyone wants to purchase a readymade factory engine and plug and play. A 427 cu in LS7 doesn't weigh anymore than a 346 cu in LS1...but it sure costs a lot more.
(About $13K) Its 505 hp right out of the crate and GM sells a computer and harness that you can plug and play for under$1K. But...the 505 HP is at an RPM well above where you need to run. The LS1 5.7 Liter may meet your needs, but why not look at getting more cubic inches in an engine that weighs the same. To increase your power down low (2000-2800 rpm) the best way is to add cubic inches. Look at buying a 427 LS7 block and putting a stroker in it. You can actually build them even bigger than 427and for a whole lot less than a factory titanium rod version.

Now, back to the direct drive scenario. Everyone is throwing up their hands and saying the engine is not designed to deal with the thrust, the harmonics, or the prop twisting and flexing.

OK, how many of you have ever looked at or measured a crankshaft in a Lycoming? The crank has a 2.375 diameter crankshaft main journal and they use it on O320/O360/O540......even a 540.

An LS1/LS7 has a 2.650 diameter main bearing. Thats over a 1/4 inch larger than a Lycoming. (Also, a conventional smallblock Chevy has a 2.65 diameter on the 400 cu in block, and 2.45 on a 350 cu in block)

Thrust face...the Chevy won't handle the thrust. Well there is where the "rub" comes in. The LS1/LS7 engine has the thrust face in the middle of the crank instead of at the rear. My opinion, thats not good, because a propellor will be pulling on the back half of the crankshaft with no thrust face supporting it. (My solution later) On a conventional smallblock Chevy the thrust bearing is at the rear of the engine. The thrust of a Lycoming is applied directly against the face of the aluminum engine case. Look at one and you will see that its not an extremely large contact area....and its directly against the aluminum....hmmmm. So while I don't know if the Chevy will handle the thrust with no problem, I've never seen any factual information showing it can't.
(Hopefully someone will jump in here and provide that info if I am wrong)

The Lycoming does have an elongated snout which contains the equivalent of two rod bearing surfaces with a space in between.This purportedly provides the strength to resist the prop side loading. It does a good job. It would seem that if a small housing were made that could support a set of those bearings and an oil supply and return routed to it, then one would have a virtual equivalent of the Lycoming . A short shaft would have to be made to bolt to the Chevy and protrude thru the housing for mounting the prop.

The LS1/LS7 also has a crankcase which extends down past the crankshaft and uses 6 bolts to retain the main bearing caps...as opposed to 2 or 4 on a conventional smallblock or 2 thru studs on a Lycoming.

Another important factor here is cylinder filling. Its hard to get enough air into an engine at the lower rpms so you need air velocity. My opinion again...some generic LS1 heads will probably accomplish that task better with small intake passages than some more expensive high flowing (upper rpm) heads. That means you can buy em cheap. Am I right in this assumption...I dunno, but it sounds good. Also, Chevy is experimenting with some 3 valve heads because they can flow much more air than two valve heads...even at lower rpms. If it ever happens, it would be a nice upgrade.

Oh, I almost forgot...the crank will break. Well maybe it will and maybe it won't. They break off airplane engines so some will probably break off some auto engine conversions...if they aren't done properly. Both types of crankshafts can be bought made from the same materials, so I don't see a problem there. As for harmonics...some airplane engines are not supposed to be run in certain rpm ranges...or they may break. Auto engines may suffer the same problem, but there is equipment available to test them. Also you can put a harmonic damper on an auto engine. Everyone calls them "balancers" but the truth is that they are dampers that are designed to absorb harmonics. They are designed to work in a certain range and the rubber absorbs the harmonic vibration. Aftermarket units can be purchased which work over a broad range of rpms. The rubber absorbs the vibration and prevents it from increasing. Ever see one for an airplane engine? I haven't, but there probably is one somewhere.

As for information on conversions, Contact Magazine is a great nuts and bolts source of information, and Mick Mayall has some books out that has combined all the articles from the magazine. If you are serious about conversions, thats where I would reccommend starting.

I've rationalized a lot of things here because its what I want to make happen. If you disagree or have other ideas, feel free to state them. I'm always willing to learn...like I said, this is just my opinion.

Last comment...Weight

I purchased a 98 LS1 Firebird and removed the engine. On a scale I own it weighed 399.5 lbs without the starter and alternator, but with the power steering pump still attached and some water in its block. The starter and altenator showed 21 lbs. It had the factory welded tube exhaust manifolds attached also. No flywheel. I had the scale calibrated a few years ago and assume its accurate as I have only used it a few times....again I could be wrong but at least it something other than speculation.
Even a Merlin engine used a gear reduction unit.

#### HoneyMoneyToo

##### Member
Yes, the prev post was right about the weight, they all differ but are very close to that number. If you were using a LS motor I would most certainly put a thrust bearing for forces applied from the prop. They are not designed to take those types of forces and would have premature failure some where in the bottom end.

My truck was dynoed for 408 HP and 476 TQ at the rear wheels. That means I am making "about" 450 and 500 at the crank. That is on 100 shot with a 228R Texas Speed (228/228 .588/.588 114LSA) cam other than that and a tune and bigger fuel injectors the motor is all stock. From what I have found on the online forums (performancetrucks.net mostly) the stock bottom ends will hold up to about 600 HP and I believe that is a 4 bolt main in the LQ9? I am not sure so don't quote me on that.

Also you can send your stock heads to Texas Speed and for $750 they will port/polish them, they are aluminium from factory flow good and cheap so why not? You can get a New aluminum 6.0 block for$1,200 or a bigger bore LS3 for $1,600... I bought my LQ9 at a swap meet from a junk yard,$1,500 for wiring harness, gas pedal, computer, and complete engine with alternator/PS pump ect with a 3 month warranty. It is an iron block but im sure you could find an aluminium one and bore it out and get all new bearings (thats a new motor) or buy new. You would still have less than $10,000 in it and another$5,000? for the reduction drive or direct drive, just need something to carry the thrust to the block through the transmission mounts (mine has 6-7 bolts with 2 thick dowels to line it up) but I am saving $20-25,000 over the "Certified" motors. BUY a BRS parachute with left over$ and you will be golden. Don't put all your eggs in one basket, if they both fail, it was time for you to go "home".

Maybe in 20-30ish years when I am 50-60 I can afford a new $50,000 engine for my$200,000 velocity (with my BRS parachute built in)

Also, I have 2 engines (5.3 Iron blocks with aluminum heads) wiring harnesses, computers, HP Tunners tuning software, ect. if anyone reading this wants to build a test engine (LS based) from the parts or try to develop some parts/engine that are for "experiential aviation" purposes.

#### Midniteoyl

##### Well-Known Member
A quick Google search shows a couple of article were they got 100+ HP on both the 4.8L and 5.3L by simple head and cam swaps..

#### ekimneirbo

##### Banned
Yes, the prev post was right about the weight, they all differ but are very close to that number. If you were using a LS motor I would most certainly put a thrust bearing for forces applied from the prop. They are not designed to take those types of forces and would have premature failure some where in the bottom end.

My truck was dynoed for 408 HP and 476 TQ at the rear wheels. That means I am making "about" 450 and 500 at the crank. That is on 100 shot with a 228R Texas Speed (228/228 .588/.588 114LSA) cam other than that and a tune and bigger fuel injectors the motor is all stock. From what I have found on the online forums (performancetrucks.net mostly) the stock bottom ends will hold up to about 600 HP and I believe that is a 4 bolt main in the LQ9? I am not sure so don't quote me on that.

Also you can send your stock heads to Texas Speed and for $750 they will port/polish them, they are aluminium from factory flow good and cheap so why not? You can get a New aluminum 6.0 block for$1,200 or a bigger bore LS3 for $1,600... I bought my LQ9 at a swap meet from a junk yard,$1,500 for wiring harness, gas pedal, computer, and complete engine with alternator/PS pump ect with a 3 month warranty. It is an iron block but im sure you could find an aluminium one and bore it out and get all new bearings (thats a new motor) or buy new. You would still have less than $10,000 in it and another$5,000? for the reduction drive or direct drive, just need something to carry the thrust to the block through the transmission mounts (mine has 6-7 bolts with 2 thick dowels to line it up) but I am saving $20-25,000 over the "Certified" motors. BUY a BRS parachute with left over$ and you will be golden. Don't put all your eggs in one basket, if they both fail, it was time for you to go "home".

Maybe in 20-30ish years when I am 50-60 I can afford a new $50,000 engine for my$200,000 velocity (with my BRS parachute built in)

Also, I have 2 engines (5.3 Iron blocks with aluminum heads) wiring harnesses, computers, HP Tunners tuning software, ect. if anyone reading this wants to build a test engine (LS based) from the parts or try to develop some parts/engine that are for "experiential aviation" purposes.
I have a couple of LS1 blocks. They can only be overbored slightly and the early ones can only
be honed ....so there is not much you can do unless you have Darton sleeves installed. By the time you do that I think its better to buy an LS3 ($1700) or LS7 ($2700) Block. The LS 7 has some additional features besides just a larger bore. Realize that if you operate either of these two engines (LS3 with 4" stroke) (LS7 ) at an rpm range of 3000 (3500) or so , the ports in the heads will
not need to be large, and in fact, something like stock LS1 heads should work well. Just clean them up and blend them near the valve seats. Haven't checked lately, but last time I bought some LS1 heads, they could be had for as little as $100 a pair. There is also a couple of aluminum SUV or Truck heads that flow like the LS6 but have bigger combustion chambers...which works out well for keeping compression low. The thing is that if you plan to do something like this, I'd sell the engines you have and get the block and heads you plan to use....rather than put money into experimenting with something you can't use later. Once you have the block and heads, most other components will have similar prices because you don't need the high performance parts. A truck intake gives more low end torque and you can get them as new take offs with the fuel rails and injectors for maybe$150. What ever you buy, remember that you are only turning 3000 rpms so
air flow will be just fine with low performance parts. Don't waste money on a high performance cam if a stock truck cam will give the low rpm power. I have some info on reccommendations for cam selection. The crux is that its all about cylinder filling. You only need to get half as much air into the engine in one minute at 3000 rpms. Don't need bigger injectors or throttle body.

How do you like your HP tuners software?