Just wondering what most F/I guys are using for a head gasket?

 

Stock.

 

Yep!

 

Is there any truth to the head gasket that lowers your comp one full point?

 

You mean like in going from 11:1 to 10:1? That would be a pretty thick head gasket, wouldn't it?

 

just something I heard

 

A thicker than stock headgasket will lower the CR.

I'm using the very effective stock hedgasket.

Some are using 2mm or 3mm Cometic headgaskets, some of which keep blowing out when used with ARP headstuds meant for a H23.

The FI forum FAQ has a chart listing CR's with different headaskets.

 

I forget the numbrs, but I think the 3mm head gasket lowered compression to 8.5:1!!! And that the 2mm lowered it to something in the 9s. I'll search and correct myself.

Edit:
2mm (1.88mm) head gasket = 9.83:1 CR
3mm (3.04mm) head gasket = 8.86:1 CR
https://www.s2ki.com/forums/index.php?showt...0&#entry5991746
I was close!

 

hmmm Now my question is will changing the gasket hurt the motor when boosted or will it still run strong. And would just replacing the stock gasket with a cometic benefit?

 

People install the Cometic gaskets to lower the CR, which allows them to run more boost, on pump gas.

The "proper" way to lower the CR is by changing the pistons. The stock FRM bores are not friendly to aftermarket pistons, so the block must be sleeved, then new pistons fitted. This cost lots of $$, and a gasket change is cheaper and easier.

A stock motor with a Cometic gasket will loose lots of power. Even a low boost SC system will loose power due to the decreased CR. In order to take advantage of the lower CR, you need more boost.

It's not as simple as install this gasket with this turbo and make XXX hp.

Any S2k making over stock HP can expect to have a shorter lifespan than a stock motor.