5.7steven

Hello everyone , i just got my rotating assembly from texas speed today , i custom spec this with someone over the phone , im running boost about 10 psi at the momment and running pump 93 so i wanted to lower my compression ratio to the 9.8:1 range but after putting everything in the calculator i see that im 8.98:1
i have weisco 3.903 bore -11 cc valve relief flat top pistons
texas speed h beam 3.6125 rods
texas speed 3.622 stroke crank
stock 241 heads
stock .051 head gasket thickness
my question is , can i decrease my head gasket thickness to get closer to my target? i really dont want to ship my stuff back because ive waited over 2 months and countless phone calls and delays and different story's to get my rotating assembly.

NAVYBLUE210

Thinner gasket will definitely help, but I think you will need to mill the cylinder heads to get to your target.

5.7steven

i agree , but i think im okay with sticking with low 9 for compression since im building a street boost motor

LS1Formulation

iTrader: (13)

Did you account for piston deck height, ring land volume, and gasket bore diameter as well? If not, your compression ratio is likely even lower than you thought. Measure your deck height before buying thinner gaskets. Typically, aftermarket pistons will have a slightly shorter pin height to account for decking the block. Stock LS pistons are generally about .005-.009 out of the hole. Depending on how your pistons were made, they could be out of or in the hole, or at zero. You won't know unless you measure. You don't want to switch to, say, a .041 gasket and find out that you're .015 out of the hole with only .026 quench. When things expand, you could be slamming the piston into the combustion chamber. Worst case scenario, obviously, and not likely - but better to be safe than sorry.

wlink14

Run what you have, it will do great with boost and 93 octane. You might be giving up 15hp with the lower compression, but 1 more pound of boost will more than fix that.