bkbailey85

Time to rebuild the LS1 in my 02 SS. 243 heads (64cc), 222/228 .581/.588 114LSA (CA smog), and 0.036 Cometic gaskets. After doing CR calculators my static is 11.1:1 and dynamic is 9.127:1. If need be I can go to 0.052 gaskets and be at static 10.65:1 and dynamic 8.78:1.

Anybody else run pump gas with similar CR numbers?

redtan

iTrader: (5)

That doesn't seem right. How advanced is that cam?

My guess is you've entered the wrong info into the calculator.

Nostang

iTrader: (4)

You will be fine with pump gas and that compression/cam combo. You are probably more like ~ 8.2 dynamic with your combo. Just hope you don't have trouble with CA inspections. My combo is a 12-1 383ltx with 259 267 cam 108lsa and I am at 9.3-1 dynamic....I won't risk running pump gas with my combo.

KW Baraka

iTrader: (7)

No. Keep the thinner gaskets.

It's better to optimize quench than it is to drop compression at the cost of losing good quench.

If quench is optimized (.030" to .035"), I wouldn't much worry about DCR.

KW

DavidBoren

Agreed. If your quench is correct, then I wouldn't change the gaskets. That dynamic compression does seem a little on the high side, though, maybe try a different calculator. I don't know. But I would not change the squish once you get it to the proper .030"-.035".

JimMueller

iTrader: (9)

When you're referencing the optimum quench of .030"-.035", are you referring to a hot motor after the aluminum has expanded? I read somewhere that aluminum will expand ~.004" when hot.

Would you rather use 1) a .045" head gasket giving .034" cold quench (~.038" hot) and 11.3 SCR or 2) a .040" head gasket giving .029" cold quench (~.033" hot) and 11.47 SCR?

KW Baraka

iTrader: (7)

I have no idea what you're talking about.

KW

JimMueller

iTrader: (9)

I'm talking about the thermal expansion of the aluminum head and block as it warms up.

https://ls1tech.com/forums/generatio...too-tight.html

https://ls1tech.com/forums/generatio...e-comfort.html

https://ls1tech.com/forums/generatio...al-quench.html

DavidBoren

JimMueller, the first option you listed using the .045" gasket looks like the safest bet, and keeps you right where you want to be, both hot and cold.

Exidous

iTrader: (11)

Do not use a .036" gasket. Unless you know exactly what your pistons are out of the block at TDC. I run a .040" on a SBE and I'd consider it as tight as you'd want to go. Don't over think the quench. It's well proven that .030"-.035" is ideal. I had a conversation with Tony Mamo about this when I was measuring rock on all my pistons before bolting on a set of his heads.

That combo should not have an issue in CA as long as the tuner is competent.

What are the .006" numbers for the cam as well as the advance?

I'm guessing those are XE-R lobes. Intake duration is 271* @ .006". Assuming 3* advance IVC should be 66.5*. Making SCR/DCR with the .036" 11.19:1/8.76:1. With the .040" you'd have 11.08:1/8.68:1.

Assumes a 111 ICL, XE-R lobes, 3.91" bore HG & .008" above deck pistons. Fore safety with the quench I'd go with the .040" gasket.

As the gas in CA is poo I'd again go with the lower SCR. I'm able to run 11.56:1/8.96:1 but I'm using 98RON(93RON/MON). Also able to run a LOT of timing all due to the awesome quench. About *31 at peak tq. Above that it lost power.

heykw

G Atsma

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