I have ported LS6 heads with 64cc chambers and an MS3 cam. the pistons I am putting in have -2cc valve reliefs. would milling the heads to 60cc's be too much? I am wanting to raise compression to make a little more power. I plan on running a 150 shot of nitrous sometime in the future.

 

ptv clearnace check is the only real way to determine for sure.
i do not like to mill more than .030 of any ls head

 

i think a mill of .015 would be ideal for you. correct me if im wrong, but i think that should get you to 62cc's = 11:1 comp with some cometic .040 head gaskets. with that, you should still be able to run 91 pump gas.

-f8l


edit: ^^ that was for stock pistons. for -2cc pistons, i believe you would want a .030 mill to achieve 11:1 compression (if thats what your looking for).

like nemeSS said, always check PTVC just to be sure.

 

so with 64cc chambers to start with, milling .030 off will give me 11:1 compression since i have -2cc valve relief pistons? will I still need to check the PTV clearance?

 

i believe you will get 11:1 with a .030 mill. hopefully someone else can verify that.

its always nice to check PTVC just to be sure and have that extra feeling of safety, but... you dont have to.

 

Here abit of a useful help

http://www.c5frc.com/calculators/Com...Calculator.htm

 

theres an even better one in some sticky.. it has like DCR and SCR based on valve events and some other BS like that. Also you could mill them .020 then run .030 gaskets and that would be very close to milling .030 and running .040 gaskets (granted your using stock .052 or .054's now). Because then if there was a problem, you could swap in thicker gaskets like the .040's and youd be golden.

 

thanks a lot! anyone know the height of a stock 2002 mls head gasket?

 

I don't think PTV is going to be an issue with the valve reliefs.