sreve

iTrader: (3)

i am in the process of rounding up the parts for a head swap.
i need to know how thick the stock head gaskets are.
i will be swapping to patriot S2s 64cc
the ls6 uses this chamber size with a comp ratio of 10.4:1
though the ls1 has 66cc chambers and 10.2:1
i have been shopping for head gaskets and was wondering what
a set of .030 cometic gaskets would do for the compression ratio?

KCS

iTrader: (20)

A .030" gasket would probably blow up your engine. On a stock bottom end, there wouldn't be enough quench, things touch that aren't supposed to touch, and motor comes apart.

Stock, the piston comes about .007-.010" above the deck. A .050" gasket gives you a nice .040-.043", while a .030" gets you about .020-.023" which just isn't enough.

sreve

iTrader: (3)

so a stock gasket compressed is nowhere near .030? as far as things touching
that should not be a problem as i only have .531 lift on 1.7:1 rockers.
the itty bitty cam in my sig is a torque monster. some hogged out heads could
take some off the low side. to counter that raising the compression ratio to the high 10s
could be the best of both worlds.

cws T/A

iTrader: (3)

KCS is saying that the piston's come out of the cylinder bore of the block .007'' - 0.010'' , using the .030'' thickness gasket could cause the piston's to actually ram into the bottom of the cylinder head itself . The quench distance between the pistons and the cylinder head is not enough .

Better choice would be the 3.910'' bore / .040'' thickness cometic .

KCS

iTrader: (20)

Exactly. It's not the valves, it's the head that the piston will crash into. Just get stck gaskets and call it a day. Cheaper, more reliable, and larger margin of safety.

sreve

iTrader: (3)

ok i gotcha, much more clear now.
so i'll buy some stock mls gaskets and mill the heads
thanks to you both for the reply

SOMbitch

iTrader: (8)

GM MLS = .054 compressed.