[Z06] Forged or cast?
Thread Starter
8th Gear
Joined: Jan 2005
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Forged or cast?
Does the 02-03 ZO6 come with forged or cast pistons. It seems like I saw that they are cast for some reason. If so, how does that limit your options for supercharging? Are engines melting down? Is this the weak link of the car? Why do you think, assuming they are cast, that they wouldn't put forged pistons in a car of this performance calibur?
Safety Car
Joined: Nov 2003
Posts: 4,979
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From: San Diego, CA "leaf" "tee" "e"
The pistons aren't just cast, they're hypereuretic. Forged pistons are noisy compared to anything else.
The rods aren't the weak link, the rod bolts are, followed closely by the valve springs and the harmonic damper (not keyed and it falls apart too).
The rods aren't the weak link, the rod bolts are, followed closely by the valve springs and the harmonic damper (not keyed and it falls apart too).
Team Owner
Joined: Oct 2001
Posts: 56,381
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Originally Posted by Cap'n Pete
Aren't the rods actually the "weakest link" in the LS1/LS6 engines?
GM is raising the bar with the new Z06 though
. Forged pistons and titanium rods in the LS7
.
GM is raising the bar with the new Z06 though
. Forged pistons and titanium rods in the LS7.
Safety Car
Joined: Oct 2000
Posts: 4,080
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From: Allen TX
The hyper piston is installed in most OEM applications due to the more strict emissions requirements. They maintain much tighter tolerances, and thus better sealing, than a forged piston...especially during cold start-up.
This is one reason its cursed in a forced-induction application. It is not able to expand like a forged piston, and thus has less tolerance for high(er) cylinder pressures.
It's this more than the cost discrepancy itself. If you price a "racing" aftermarket hyper piston, you'll see they are not cheap. And there are plenty of cheap forged pistons out there.
I thought the LS7 was going to have forged pistons. That's too bad if it doesn't.
Back to the original question... 10.5:1 CR is what limits boosted applications more than the pistons themselves. Keep boost in the 5-6+psi range with a good, conservative tune and the motor will live a long time. Detonation will nuke any piston...hyper or forged.
This is one reason its cursed in a forced-induction application. It is not able to expand like a forged piston, and thus has less tolerance for high(er) cylinder pressures.
It's this more than the cost discrepancy itself. If you price a "racing" aftermarket hyper piston, you'll see they are not cheap. And there are plenty of cheap forged pistons out there.
I thought the LS7 was going to have forged pistons. That's too bad if it doesn't.
Back to the original question... 10.5:1 CR is what limits boosted applications more than the pistons themselves. Keep boost in the 5-6+psi range with a good, conservative tune and the motor will live a long time. Detonation will nuke any piston...hyper or forged.
