What gaskets are everyone using on ls3's? The closest gasket i've seen is the stock ls3 gaskets that say they can take up to a 4.080 bore. Are there any thinner gaskets for a 4.070 bore than 0.051? How close does the gasket need to be to the actual bore size?

 

I've built an LS3 crate motor for my camaro. The LS3 gaskets measured 4.100 diameter and they are supposed to be .054 thick.. The stock LS3pistons were out of the block by .010.

I ended up using LS7 Gaskets on my LS3. They were 4.160 Dia and are .051 thick. My heads have had the chambers CNC'd and the LS3 gasket was a little smaller than the chambers. I did not want the gasket sticking out into the chamber. If the chambers are stock I would stick wih the LS3 gaskets. Make sure you have at least .035 quench clearance.



Dee Jay

 

I got 4.085 Cometics .051 thick for my engine. I am pretty sure I got them from TSP.

 

I'm using Cometics at 4.085 bore, .036 thickness on my LS3 crate motor, for more compression and better quench (.036 is what I'd consider bare minimum thickness). Some people have complained about coolant leakage issues with Cometics on LS7s, but I've used them for 1000s of miles on both an LS1 and LS3, street and HPDE, without any problems.

 

ls7 gaskets-

even on cnc l92 heads-

 

Would a .040 thick gasket with a 4.060 bore size be sufficient? Since only .005 would be sticking out?

 

Not if it's smaller than the bore. Never use a gasket that's smaller than the cylinder bore.

 

It's a stock LS2 bore... 4.000 just didn't want to have any overhang and burn the gasket up...But the LS3 bore is 4.065....

 

Whats a safe maximum that you wouldn't want to go over the bore size?