I need a recommendation please. 355 ci. 21cc dish pistons i need an .050 gasket to stay at 9:3:1.
Will the factory .051 headgasket live on 9psi, then 12 psi of boost? Does it have a decent fire ring? Readily available is the Fel pro .039, but that will put me at 9:5:1 compression.
I thought i could use a copper set, but i would have to o-ring the block or heads....Anyone have a bettor suggestion?
Thanks
John

 

Other than the stocker I don't know of any gaskets that thick. I hear Cometic will make custom gaskets, but if so they are likely $$$. Lots of people run blowers on stock long blocks and the pistons go before the stock gaskets! But at 9 and then 12psi (and I assume heads, cam, etc.) you will be making a lot more cylinder pressure and I think there may be a problem with the stockers.

Copper gaskets are for race cars, as far as I am concerned. They always seem to seep coolant. If you had perfect deck and head preparation maybe they would be ok. FWIW, unless you have a zero deck a 0.051" gasket will not give effective "squish". I'd say you should consider the FP #1074 even though it will raise your CR a bit.

Rich Krause

 

Will .2 more compression really make that much difference in the grand scheme of things?

 

No, I doubt it will be a major issue.

Rich

 

as stated, cometic will make whatever you want, and they will hold ALOT. but they're expensive- I think they are like $125 each for custom thickness gaskets.. I could be wrong.

I ran cometics @ 25+ pounds of boost, never blew one out.

I'll be running them again on my SBC.

good luck!

 

Thanks for the help guy's...I was trying to keep compression as low as possible...(within budget too!) so it will have to live on the Fel-pro's at 9:5:1... With my 53cc (measured) LT1 chambers, .039 gasket and a 21cc dish forgings, .015 deck(assumed # from the last piston install) and .030 over i figured 9:5:1 compression....Sound right?

 

Im running the felpro #1074's and 20lbs with no problems. Oh thats with head studs too, You will need those!