2XR95Z28

iTrader: (4)

so i'm pullin the heads this winter and was looking into bumpin up the compression, i have read that impala gaskets will bump me up to right around to 11.1

I was also going to have my heads checked while i have them off and possibly milled slighly. what i was wondering is what is most compression i could run safely on pump gas as this is a street car but does see quite a bit of the track and would be run mostly on 91-93 octane.

What power increases would i see from bumping up the the 10.5:1 stock to say 11:1 or however higher i can go? i just want it to be streetable and not too high where the reliabililty suffers.

Let me know is anyone can help me out here.

THankS!

2XR95Z28

iTrader: (4)

anyone?

z2896

i do know that 12.5 is the max compression with pump gas at 93 octane, but 12:1 would be safer.

i do not know how much power you will gain from increasing your compression from 10.5:1 to 11:1. however i would assume that you will gain a decent amount but nothing huge.

Chevyguy358

iTrader: (4)

I hope that isn't the only reason that your pulling off your top end. It will increase power some but not worth the hassle

brucealmighty744

iTrader: (2)

I really have no idea, but it is a question I would like to know the answer to too. Free bump

2XR95Z28

iTrader: (4)

i blew a head gasket, so i figure while im in there i might as well get as much extra power i can while i have the heads off. I'm going to have the heads checked just to make sure they didnt warp at all and get all the valves and everything checked. I just see it as while they are off why not? Right now i'm looking into the impala gaskets plus talking to the place that is going to check my heads and see what they can mill off to bump it up a little more.

Schweet97Z

iTrader: (35)

milling the heads .010" + impala head gaskets will get you around 11.0:1 compression. while you MIGHT see a couple HP gain from the comression bump...it wont be noticeable. your real power comes from porting and a good cam selection.

Mattsz28

iTrader: (1)

I run 11.8:1 CR. No knock on 93. Key is the reverse cooling. Keep her cool and you shouldnt see an issue. I dont think you'll see noticeable gains from bumping up half a cr.

GIZMO

iTrader: (8)

I agree that you won't see much of a gain from the compression bump. If you are on a budget, I would suggest pulling the valves and doing some minor bowl work. Get a three angle valve job and have them checked for warpage (mill if needed). Install good stainless valves and upgrade the valve springs. It also might be cheaper to just install out of the box aftermarket heads.

Good Luck,

Daren

Mattsz28

iTrader: (1)

I agree with what he said. You'll see gains with porting even on a stock cam. I dont think the aftermarket heads are something that's in your price range (just saying based on your comments, not a dig), I think the cheapest I saw a set of any aftermarket castings go online was 1500$. For that you could have the heads ported, get valve train stuff, and a cam. You can pick a set of ported stockers up with a cam to match in the forsale section for less and a gwiz. Just a thought. If you want to see some gains, while the heads are off do a set of LT's. 20whp is pretty common from LT's.

2XR95Z28

iTrader: (4)

Ya i think i'm going to try to go with the hot cam and check out a local head porter around here and see if i can get a slight port and polish job done to match the cam a little better. I really dont know if i'll mess with the compression. Or do you think while i got the heads off and need new gaskets should i just get the impala ones to see if it'd help at all? i figure i have to get new gaskets anyways, or should i stick with stock height gaskets?

Mattsz28, i'm for sure getting headers while i got it all off, there's no point in puttin back on the manifolds haha.

If anyone see's any hot cam kits going cheap let me know, the cheapest i've ever seen is 300.

Chevyguy358

iTrader: (4)

chances are if you do have a blown head gasket that head may be warped in which you would need to mill it, and of course the other. Just be sure to have them checked

2XR95Z28

iTrader: (4)

I wouldnt say i completely blew out the gasket, i think it was on its way out by the signs of the coolant disapearing, but my oil wasnt too milky in the pan and i never had a huge smoke show behind the car, so i just think it was slightly leaking. So i'm hoping the head didn't warp because i never let if overheat, but i'm still going to have them all checked out while there off.

Tapout911

iTrader: (9)

Can also run the MR Gasket head gasket which measure .026 vs. the impala .029.