Using .120 cometic head gaskets.
Thread Starter
1st Gear
Joined: Feb 2019
Posts: 1
Likes: 0
Using .120 cometic head gaskets.
Hey new here first time posting and I was hoping someone here had some experience with this. 2000 Corvette LQ9 iron block forged bottom end. Cam has .637/.637 lift valves hit at 5750-6000 rpm. The shop im working with had me order .120 head gaskets to lower my compression to the 8 to 1 ballpark and provide more valve to piston clearance and .120 intake gaskets. I dont think the factory intake manifolds will bolt up due to the bolt holes being spread apart. Has anyone ran into this or know of an intake manifold that will work? Looking at twin turbos for the engine or possible a twin screw blower.
Last edited by Derek Hall; Feb 27, 2019 at 09:46 PM.
AMP Racing
Joined: Aug 2006
Posts: 10,756
Likes: 589
From: Washington TWP NJ
2023 C5 of the Year Finalist - Modified
2017 C5 of Year Finalist
St. Jude Donor '09-'10-'11-'12
8:1??? That’s rediculously low unless you’ve only got shitty gas where you are.
Also, are you saying that your valves already hit the pistons with that cam? If so, are you sure it’s degreed properly?
Also, are you saying that your valves already hit the pistons with that cam? If so, are you sure it’s degreed properly?
Drifting
Joined: Sep 2017
Posts: 1,964
Likes: 696
From: Avon Lake OH
With that much lift, you are going to need fly cut pistons (most likely aftermarket forged units, not sure if -2cc will be enough) and some stiffer valve springs, most likely something like Comp Cams 26926 duals.
You need to fine yourself a more knowledgeable engine builder.
You need to fine yourself a more knowledgeable engine builder.
Burning Brakes
Joined: Oct 2016
Posts: 1,209
Likes: 363
From: Massillon Ohio
As everyone else has said, your engine builder is an idiot. I would not give them anymore of your money. There is no reason to have an 8:1 engine, and a 0.120" Gasket?!?!?! That is ridiculous.
Racer
Joined: Apr 2009
Posts: 359
Likes: 25
From: San Antonio TX
You should run different pistons with a thinner gasket. That much quench area is not a good way to get compression down. If the piston to valve clearance isnt enough, cut the pistons. You shouldnt have intake manifold fit issues, but there is a decent chance that will cause worse performance than doing it right.
Are you trying to reuse a set of pistons you already had, or did they recommend these pistons? Also, what is your piston to deck clearance?
Are you trying to reuse a set of pistons you already had, or did they recommend these pistons? Also, what is your piston to deck clearance?
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski