SmokedOutZ28

iTrader: (35)

Has anyone use a head gasket .120'' thick on boost?

I have a NA car with a decent amount of compression for a nitrous hit and I'm getting the itch to swap to FI but don't want to tear into my motor to drop the compression (piston swap). Ive been told that cometic makes a .120'' gasket and with that It will lower my compression down to 10.1 with the engine as it currently sits right now does that sound smart and safe? looking to make 8-12lbs of boost on 93 octane. 700-800 rwhp through T56.

My other option was 11.24 with .060'' gasket but I think that might be too much for pump gas.

sr71bbjr

iTrader: (52)

Run e85!

blue00ZZleeper

iTrader: (5)

Try a set of heads with a larger combustion chamber coupled with a thicker gasket and get the compression a little lower. That's a pretty thick gasket....I don't know if I'd want to put it against high cyl pressures.

XtremeDime

iTrader: (16)

Ya, thats seems a bit thick to me.

NemeSS

iTrader: (127)

if was me, i would prep the motor correct for forced indution. imo a thicker head gasket would be the last thing i would consider. to drop scr.
if anything i prefer my gasket to be thin as necessary to achieve a .035-.040 quench area. forced induction or n/a,etc.
options are either correct piston and heads chamber to lower scr
or run your car with current parts, fulltime on race or e85

mpatton

Curious as well. Im gunna run 243s and thicker gaskets but don't know how thick

Whistler

iTrader: (46)

Run 317 heads for bigger chambers.

SmokedOutZ28

iTrader: (35)

Thanks guys for the input. I've thought about E85 but in my area there is only one gas station that sells it and I like to take the car on decent mileage trips within the state and don't want to run into a issue of not finding E85 somewhere.

by chance whats the chambers of the 317 heads?

blue00ZZleeper

iTrader: (5)

72cc but you can always have them opened up a little bit.

rotary1307cc

iTrader: (5)

this^

mpatton

So. Would you recommend stock thickness with 243s and e85 on a stock ls1 that's soon to be boosted?

mpatton

243s will not be ported either. I was informed not to port them since it wont be an n/a car much longer. Any insight on that as well.

blue00ZZleeper

iTrader: (5)

A set of 317's on a stock compression LS1 with .035" gaskets should put you around 9.5-9.6:1. With the 243's it should bump you up into the higher 10.0:1's somewhere. With E-85 you can definitely get away with a higher compression then pump gas. Just remember you need the fuel system to back it up. I would also look into getting them ported. I really don't care how many people say its not important, truth is its not AS important as a N/A setup but nevertheless increasing airflow raises the combos efficiency. The more efficient it is, the more power it'll make.