Kinda sad about all the engine specs
01-23-2018, 10:28 PM
#61
Torque
Ferrari 812 Superfast 530 lb-ft
Reliability
Honda S2000 9,000 rpm for hundreds of race hours, no valve drop, no mess
Yes, you can have a high revving n/a engine with both torque and reliability. Heck, making a V10 or V12 engine out of either S2000 or E46 M3 tech will get you lots of torque and power reliably. By now most of Audi's V10s should be plenty reliable and offer a fat power band.
Too many enthusiasts are armchair specialists nowadays. That is the real reason we get turbo engines with crap heads and heavy bottom end reciprocating parts. Everyone is quoting 0-60s, quarter miles, and top speeds. What did you expect? Manufacturers are selling you a car that can get those times down. Boost will outperform n/a in drag applications and that's all anyone cares about.
As for reliability with boost, good luck keeping the bearings alive with 850hp motors that make just as much in torque. Technically even the new ZR1 motor will make that much, it just loses 100hp to spin the TVS. Not to mention, transmissions, LSDs, driveshafts and so forth. A 600hp n/a motor would be an endurance motor by comparison.
The proof is in the pudding as they say. If push-rods have a harder time moving valves precisely with in block cam you'll drop a valve before a high revving DOHC will wear out its valve guides. Show me one DOHC VTEC block that has a failed cam shifting mechanism if it even exists. On paper doesn't matter. Engine building is a complicated science.
Ferrari 812 Superfast 530 lb-ft
Reliability
Honda S2000 9,000 rpm for hundreds of race hours, no valve drop, no mess
Yes, you can have a high revving n/a engine with both torque and reliability. Heck, making a V10 or V12 engine out of either S2000 or E46 M3 tech will get you lots of torque and power reliably. By now most of Audi's V10s should be plenty reliable and offer a fat power band.
Too many enthusiasts are armchair specialists nowadays. That is the real reason we get turbo engines with crap heads and heavy bottom end reciprocating parts. Everyone is quoting 0-60s, quarter miles, and top speeds. What did you expect? Manufacturers are selling you a car that can get those times down. Boost will outperform n/a in drag applications and that's all anyone cares about.
As for reliability with boost, good luck keeping the bearings alive with 850hp motors that make just as much in torque. Technically even the new ZR1 motor will make that much, it just loses 100hp to spin the TVS. Not to mention, transmissions, LSDs, driveshafts and so forth. A 600hp n/a motor would be an endurance motor by comparison.
The proof is in the pudding as they say. If push-rods have a harder time moving valves precisely with in block cam you'll drop a valve before a high revving DOHC will wear out its valve guides. Show me one DOHC VTEC block that has a failed cam shifting mechanism if it even exists. On paper doesn't matter. Engine building is a complicated science.
01-24-2018, 06:24 PM
#62
Safety Car
Had the F20C. GREAT engine. Would hit 9.3K fuel cut weekly. Bought at 50K, sold the car at 130K, still ran perfectly. Still, having to adjust valve lash every 30-40K - while easy - was always at the back of my mind. All roller lifters, very light valve train but noisy as sin. DOHC but it was almost a gear drive cam - chain drive to an idler with the idler directly gear driving the dual cams. If you mis-shifted on the car though, kiss that engine goodbye.
Mechanical overrev will usually crack the valve retainers on F20C but not enough to grenade the motor unless you did it again before replacing them. A common fix is to use the F22C retainers which could take more abuse. I skipped the mod and never had issues.
01-25-2018, 08:57 AM
#63
Safety Car
Adjusting the valve leash is a small price to pay for an exotic powerplant. Small ding in maintenance budget. Noisy, well sure. Still passed Laguna Seca's 90db meter, even with the filter cover removed. The C7Z would hit 97db in 4th at part throttle to get you booted off the track. I would venture a guess that even if you jam the exhaust in stealth mode, it would still fail to pass the 90db test. I'm being a bit coy of course, as the noise at idle is on the high side with the F20C.
Mechanical overrev will usually crack the valve retainers on F20C but not enough to grenade the motor unless you did it again before replacing them. A common fix is to use the F22C retainers which could take more abuse. I skipped the mod and never had issues.
Mechanical overrev will usually crack the valve retainers on F20C but not enough to grenade the motor unless you did it again before replacing them. A common fix is to use the F22C retainers which could take more abuse. I skipped the mod and never had issues.
01-25-2018, 06:16 PM
#64
Safety Car
I planned to swap in an LS7 as well. Then I thought, why not buy the C7Z, it will have the latest small block, trans mounted at the back, and everything scaled up to handle the torque, trans, axle, cooling 
, diff, etc. In reality the C7 Z proved to be to unreliable to run 20 minutes at a time, mostly due to powertrain design, assembly, and built quality. So it follows that today I wouldn't attempt to use just the Chevy powertrain in a chassis that already has an engine that can handle 20 minutes of use. The proof is in the pudding as they say. Maybe the LS7 is more reliable than the LT4, I'm not willing to try it anymore.
, diff, etc. In reality the C7 Z proved to be to unreliable to run 20 minutes at a time, mostly due to powertrain design, assembly, and built quality. So it follows that today I wouldn't attempt to use just the Chevy powertrain in a chassis that already has an engine that can handle 20 minutes of use. The proof is in the pudding as they say. Maybe the LS7 is more reliable than the LT4, I'm not willing to try it anymore.
01-26-2018, 06:45 AM
#65
Race Director
GM LS v8 is one of the most sought after engines in the world...only a fool would diss the LS powertrain but that's what these Internet forums are all about..
01-26-2018, 07:08 AM
#66
I get the world is turning force induction (heck I sell Mercedes and virtually every car we sell is a turbo or hybrid something)... but I was really sad about the C7 Z06 when they said they planning a high revving V8 and ended up doing the LT4 supercharged (which is a fine engine, not disputing it)...
I was hoping the DOHC talks/patents meant we were getting that engine finally in a mid engine.. but alas the CAD drawings and everything
The C7 grand sport with the voodoo v8 flat plane crank Ford GT350 engine would have made that car perfect... 8250rpms redline, 526hp...
I do love my GS , the LT1 isnt bad at ALL... just love high revving screaming engines
-Shahul
I was hoping the DOHC talks/patents meant we were getting that engine finally in a mid engine.. but alas the CAD drawings and everything
The C7 grand sport with the voodoo v8 flat plane crank Ford GT350 engine would have made that car perfect... 8250rpms redline, 526hp...
I do love my GS , the LT1 isnt bad at ALL... just love high revving screaming engines
-Shahul
01-26-2018, 07:33 AM
#67
preaching to the choir. I loved that little car. I did miss the torque of a V8 though - the instant tire smoking power. Now, I miss the high-rev/rev matching nature of the F20C. I really want to throw in a lighter flywheel/PP package into this LS3. I think it would really really wake up the rev matching and rev-up characteristics of the LS. I never missed an upshift, but I have downshifted too early (2nd at around 65-70ish... a little under 10K RPM). Car got unsettled but no damage to the engine. I did swap the intake retainers to the F22 but kept the exhaust side the same.
I would think an LS3/LS7 into a S2000 would be insane. If you wanted reliable power/torque, just keep the revs low. 400WHP out of the LS7 rev'd to only 6K or so would give you more power under the curve than most supercharged/turbo'd F20/22 engines.
I would think an LS3/LS7 into a S2000 would be insane. If you wanted reliable power/torque, just keep the revs low. 400WHP out of the LS7 rev'd to only 6K or so would give you more power under the curve than most supercharged/turbo'd F20/22 engines.
Adjusting the valve leash is a small price to pay for an exotic powerplant. Small ding in maintenance budget. Noisy, well sure. Still passed Laguna Seca's 90db meter, even with the filter cover removed. The C7Z would hit 97db in 4th at part throttle to get you booted off the track. I would venture a guess that even if you jam the exhaust in stealth mode, it would still fail to pass the 90db test. I'm being a bit coy of course, as the noise at idle is on the high side with the F20C.
Mechanical overrev will usually crack the valve retainers on F20C but not enough to grenade the motor unless you did it again before replacing them. A common fix is to use the F22C retainers which could take more abuse. I skipped the mod and never had issues.
Mechanical overrev will usually crack the valve retainers on F20C but not enough to grenade the motor unless you did it again before replacing them. A common fix is to use the F22C retainers which could take more abuse. I skipped the mod and never had issues.
01-26-2018, 03:32 PM
#68
Safety Car
preaching to the choir. I loved that little car. I did miss the torque of a V8 though - the instant tire smoking power. Now, I miss the high-rev/rev matching nature of the F20C. I really want to throw in a lighter flywheel/PP package into this LS3. I think it would really really wake up the rev matching and rev-up characteristics of the LS. I never missed an upshift, but I have downshifted too early (2nd at around 65-70ish... a little under 10K RPM). Car got unsettled but no damage to the engine. I did swap the intake retainers to the F22 but kept the exhaust side the same.
I would think an LS3/LS7 into a S2000 would be insane. If you wanted reliable power/torque, just keep the revs low. 400WHP out of the LS7 rev'd to only 6K or so would give you more power under the curve than most supercharged/turbo'd F20/22 engines.
I would think an LS3/LS7 into a S2000 would be insane. If you wanted reliable power/torque, just keep the revs low. 400WHP out of the LS7 rev'd to only 6K or so would give you more power under the curve than most supercharged/turbo'd F20/22 engines.
01-27-2018, 12:25 PM
#70
Le Mans Master
I think the Powertrain guys don't want another LT5 episode as happened in the C4 ZR1. Probably why they named the C7ZR1 motor LT5.
Last edited by Dominic Sorresso; 01-27-2018 at 12:26 PM.