LS1 pistons.....
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Melting Slicks
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From: Indian Rocks Beach FL
St. Jude Donor '08-'09-'10
Lucky, after my last experience relying on a manual I'm a little gun shy, but that's what my reference tells me. I'm using "How to Rebuild GM LS-Series Engines" by Chris Werner. Unfortunately I know he does have some errors in the book but I don't think he's mistaken about the pistons.
I do know I'm correct about the meaning of hypereutectic.
I do know I'm correct about the meaning of hypereutectic.
Tech Contributor
Joined: Jan 2007
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From: Dyer, IN
Lucky, after my last experience relying on a manual I'm a little gun shy, but that's what my reference tells me. I'm using "How to Rebuild GM LS-Series Engines" by Chris Werner. Unfortunately I know he does have some errors in the book but I don't think he's mistaken about the pistons.
I do know I'm correct about the meaning of hypereutectic.
I do know I'm correct about the meaning of hypereutectic.
GM finally got it right with the FI LS9, forged pistons and rods.
Last edited by lucky131969; Dec 22, 2009 at 12:08 AM.
Melting Slicks
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From: Indian Rocks Beach FL
St. Jude Donor '08-'09-'10
If you are sure the LS pistons are cast I'll defer.
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Tech Contributor
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From: Dyer, IN
Most factory hypereutectic pistons have a silicone percentage of 16-19. Alloys used for forged pistons have much lower percentages of silicone 11 or lower.
You don't have to believe me, I'm sure there is hours of reading on the subject on the net.
As long as I know what I have, that's all that matters:
My 99- hypereutectic
My 65- Forged
Thread Starter
Burning Brakes
Joined: Apr 2006
Posts: 787
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From: Ontario
Most factory hypereutectic pistons have a silicone percentage of 16-19. Alloys used for forged pistons have much lower percentages of silicone 11 or lower.
You don't have to believe me, I'm sure there is hours of reading on the subject on the net.
As long as I know what I have, that's all that matters:
My 99- hypereutectic
My 65- Forged
You don't have to believe me, I'm sure there is hours of reading on the subject on the net.
As long as I know what I have, that's all that matters:
My 99- hypereutectic
My 65- Forged
Hi....So we are getting close!!!!
On a 99 FRC car with a factory stock engine. Are the pistons the same quality as was installed later in the Z06 engine...........
TIA
Tech Contributor
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From: Dyer, IN
I'll let you be the judge.....I'm out....
http://www.gmperformanceparts.com/En...4322&engCat=ls
http://www.gmperformanceparts.com/En...1268&engCat=ls
Thread Starter
Burning Brakes
Joined: Apr 2006
Posts: 787
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From: Ontario
.
I'll let you be the judge.....I'm out....
http://www.gmperformanceparts.com/En...4322&engCat=ls
http://www.gmperformanceparts.com/En...1268&engCat=ls
I'll let you be the judge.....I'm out....
http://www.gmperformanceparts.com/En...4322&engCat=ls
http://www.gmperformanceparts.com/En...1268&engCat=ls
I'm thinking of adding NOS to my 99 and was cautioned because of the quality of pistons. That they were as not as good as the Zo6 piston, hence would not take the abuse....
Thanks for the help
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St. Jude Donor '09-'10-'11
There are a number of reasons why a manufacturer would choose to use hypereutectic over forged. In the case of the LS series engines, the need to keep tight bore to piston clearances for reduced vehicle emissions is one of the key reasons. Forged pistons typically have a lower percentage of silicon and require higher bore to piston clearance due to their higher coefficient of thermal expansion. The LS series engines with their short skirts, reduced mass and deck height make it a challenge to control piston type noises. Keeping tight piston to bore clearances and a low coefficient of thermal growth are a must to negate cold piston type noises. The LS9 has forged pistons and the only LS engine that I’m aware of that does. 
Last edited by Eric D; Dec 22, 2009 at 11:15 AM.
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Thanks.
