a4z28

If my motor is 10.9 with a 39. head gasket what would it be with a 93. thick head gasket? thanks

Injuneer

You are asking about going from an 0.039" compressed thickness gasket to an 0.093" gasket? I didn't know they made one that thick for the LT1.

a4z28

Not for my lt1 for my 434 sbc trying to go supercharged . I want to get the compression down so i could run on pump gas than at the track switch to race fuel and pulley it, trying to figure out where i would be at compression wise. thanks

Injuneer

Did you use the compression ratio calculator linked in the automotive calculations post, sticky at the top of the Advanced Tech page?

AdioSS

I wouldn't sacrifice good quench to lower the compression ratio. Could cause other issues.

From looking at your sig, it might be better to leave the engine as is (maybe change the cam advance) and just switch from pumpgas to racegas?

a4z28

Well i heard quench isnt important with forced induction as if it was naturally aspirated. I am propably just gonna leave it as and shoot fire ot of it and see where it goes, than if it blows 18's and a blower are in order.

BigBadLou

When installing forced induction on an engine, I wouldn't use a thicker head gasket. I'd go the other direction and try to get the HG as thin as I could. The general rule is that you don't want to increase the face surface of the gasket in the chamber, especially with increased cylinder pressure.

Lou

rskrause

Don't worry about quench with forced induction. Makes no difference due to all the turbulent flow created by positive pressure in the manifold. What gasket is that thick? The only ones I know of are copper. Copper gaskets usually leak, sometimes a little and sometimes a lot. I don't think they are a great idea for a street car.

FWIW, you would have serious alignment issues with the manfold and intake ports with that extra 0.050".

Rich