Stock Engine Limits
Thread Starter
Launching!
Joined: Dec 2005
Posts: 213
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From: San Antonio TX
Stock Engine Limits I have searched and can not find the exact answers im looking for so I figured I would ask you guyz .
What are the stock limits of the:
Pistons
Rods
Crank
I know that the Pistons are probably the weak link, when do they reach there limit? Also what kind of power are people putting down on stock block LS1s?
What are the stock limits of the:
Pistons
Rods
Crank
I know that the Pistons are probably the weak link, when do they reach there limit? Also what kind of power are people putting down on stock block LS1s?
Rods are by rpm I am pretty sure. 01-02 motors have the better bolts and can take up to 7000 and the pre 01's are not safe near 6800ish. The crank supposedly is indestuctible. Some guys on here are pushing 1000hp on stock crank. Buddy of mine that worked at HCI told me the pistons are good for 530ish rwhp. Beyond that, you risk them failing.
TECH Apprentice
Joined: Aug 2004
Posts: 321
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From: Buffalo, N.Y.
'01-'02 LS1 performance builds are probably limited the most by the rod bolts. Even though they are the strongest OEM bolts offered, I wouldn't push very far past 500HP/6,800 RPM. Yeah, they'll rev to 7 grand, but I wouldn't make a steady habit out of it if it were my car.
Cranks ARE incredibly strong, as are the rods. The flat-top hypereutectic pistons do not like crazy amounts (say, over a 100-shot) of nitrous as a steady diet, either. Two other suspect parts to keep in mind when doing a performance build are the OEM pushrods, and valve springs. All-in-all, for an aluminum engine, it's for real. If you want to venture much above the 500HP mark, it's time to consider hi-quality, strong, aftermarket parts. The OEM crank IS insanely strong for an OEM cast iron piece, and I'm sure guys do push them to 1,000HP, but if it were me, I'd start looking at a forged crank at 700-750HP.
Your PCM will not protect your engine against a mechanically-induced (missed shift) over-rev. The rev limiter works only if the engine is being accelerated through use of the throttle. If you get too happy with your right foot and "hit" the rev limiter, the PCM pulls fuel from the cylinders to limit RPM. If you stuff your shifter back into 1st at 6 grand (missed 2 to 3 shift), the engine is being mechanically over-reved through the transmission....your PCM cannot control that type of over-rev. That's when pushrods bend/break, pistons smack into open valves, and all other kinds of good stuff.
Cranks ARE incredibly strong, as are the rods. The flat-top hypereutectic pistons do not like crazy amounts (say, over a 100-shot) of nitrous as a steady diet, either. Two other suspect parts to keep in mind when doing a performance build are the OEM pushrods, and valve springs. All-in-all, for an aluminum engine, it's for real. If you want to venture much above the 500HP mark, it's time to consider hi-quality, strong, aftermarket parts. The OEM crank IS insanely strong for an OEM cast iron piece, and I'm sure guys do push them to 1,000HP, but if it were me, I'd start looking at a forged crank at 700-750HP.
Your PCM will not protect your engine against a mechanically-induced (missed shift) over-rev. The rev limiter works only if the engine is being accelerated through use of the throttle. If you get too happy with your right foot and "hit" the rev limiter, the PCM pulls fuel from the cylinders to limit RPM. If you stuff your shifter back into 1st at 6 grand (missed 2 to 3 shift), the engine is being mechanically over-reved through the transmission....your PCM cannot control that type of over-rev. That's when pushrods bend/break, pistons smack into open valves, and all other kinds of good stuff.
What about hp limits on a road course. Drag racing is one thing, but what can our engines take as far as beating on them for an extended period of time? Obviously you can over build and get the strongest parts possible but not all of us are rich enough to do that.
