Head gasket thickness?
Thread Starter
Teching In
Joined: Feb 2017
Posts: 3
Likes: 0
Head gasket thickness? I have made the decision on which head gasket to use but I do not understand the reason for so many choices on the thickness (from .027 to .051). How do you make the right decision on which one is best for your application? Stock bottom end LS1 has H/C/I. Adding a Procharger. Boost will only be 8 psi.
They make different head gasket thicknesses for controlling the quench/squish. Measuring how far the pistons come out of the hole on your engine, will control how thick you want your head gasket from what I understand. The closer you can "safely" get the piston to the head the better. But you don't want to get too close, or you risk running the piston in to the head. I'm not sure what the perfect quench/squish measurement is, but there is a minimum number you want to abide by. I think the general guide line recommended is a .040" quench/squish.
I read this post by J-Rod, and he explains is pretty well.
https://ls1tech.com/forums/advanced-...tance-ls1.html
I read this post by J-Rod, and he explains is pretty well.
https://ls1tech.com/forums/advanced-...tance-ls1.html
For a supercharged application, you want to run a 9-layer headgasket. Something that can deform but still trap boost.
The LS9 from GM is probably the best out there for the price. It's an .051" MLS gasket.
Cometic makes the MLX for boost and Fel-Pro has some as well.
And the quench is the distance from the combustion chamber to the piston. As a stock shortblock, your pistons come out of the hole .006" or so. A .040" gasket gives you a quench of .034" which is right about the edge of a street car. A tighter quench gives you the ability to fight detonation and run higher compression/dynamic compression/timing with all things being equal.
I would back off the quench to .045" for a mild blower application. That's about where the LS9 gasket comes in for you. It's still plenty tight. Most would say around .040-.045" is better for a street car anyway. If you wanted to run 20+PSI, I'd probably try to run as tight as possible .030" or so to help control detonation.
However, import and Ford guys don't even have quench pads. It's not as important as it is for NA. I'd just build it for the desired compression and use a gasket that won't torch your motor.
The LS9 from GM is probably the best out there for the price. It's an .051" MLS gasket.
Cometic makes the MLX for boost and Fel-Pro has some as well.
And the quench is the distance from the combustion chamber to the piston. As a stock shortblock, your pistons come out of the hole .006" or so. A .040" gasket gives you a quench of .034" which is right about the edge of a street car. A tighter quench gives you the ability to fight detonation and run higher compression/dynamic compression/timing with all things being equal.
I would back off the quench to .045" for a mild blower application. That's about where the LS9 gasket comes in for you. It's still plenty tight. Most would say around .040-.045" is better for a street car anyway. If you wanted to run 20+PSI, I'd probably try to run as tight as possible .030" or so to help control detonation.
However, import and Ford guys don't even have quench pads. It's not as important as it is for NA. I'd just build it for the desired compression and use a gasket that won't torch your motor.
Last edited by JakeFusion; Feb 2, 2017 at 09:35 PM.
