i thought i had about 9.5to1 with 64cc stock heads but come to find out i had 10.2 i bought a set of afr 195cc milled to 58cc so im stuck with them now but should i be alright with 92 octane gas? thanks

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1992 camaro RS
373 10 bolt rearend
ssm sfc's
87 350 TPI
bored 30 over
compucam 2032 with 1.6
482-495 LIFT 214-220 duration full roller rockers
msd6AL
1 5/8 headman headers
2 `1/2 flowmaster exuast
k&n filters gutter air box gutted maf
3 pc under drive pulleys
no emissions no egr etc
custom ED Wright chip
eddelbroc intake base and runners ported plenum
midly ported and polished stock heads
Taylor 8mm wires
B&M mega shifter
gutted maf/airbox
hotchkis lower control arms
3" exhuast cutout
homemade cold air intake
2000 tci stall
700R4 with B&M shift kit
new best ET 13.5 @104.66

 

10.2 is just fine for a port fuel injected engine, as long as you stay with 92 octane. I'm building my 385 CID minirammed engine with 10.75:1 compression. TPIS tells me that they build their street engines with CR up to 11.25:1!!

You'll just have to make sure your knock sensor works well, and you'll definitely want to custom-tune your engine's chip with Tunercat or equivilant.


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Daniel Burk
http://www.isthq.com/~dan/fcar.html
'84 Trans Am WS6/L69
KB SFC, Moser axles, Torsen Diff. PST suspension, Braided stainless brake lines, Koni struts, 11-inch rear disks,Spohn Adj. torque arm,
Ported 305 heads w/1.94"intake valves, Comp Cams XE262H, Griffen alum. radiator,
Turbine Technologies 2500 stall converter, underdrive pulleys, Crane Hi-6 & more.
1.05g skidpad verified.
New best E/T! 14.039 at 100.82 MPH in 41 degree air at Stanton, Michigan.

 

58 is cutting it close. I know of several 54cc chambered head cars running 10.75 without a whimper.

 

You'll be fine. Especially with the aluminum heads. They pull heat out of the combustion chamber, which means you can run higher compression ratios with aluminum than you could with iron heads. The real key is your camshaft's duration numbers. Longer duration numbers require higher compression ratios, shorter durations need lower numbers. This is because the static compression ratio and the camshaft's duration combine together to create what is called a dynamic compression ratio, which is more realistically the actual compression pressure your combustion chamber will see during actual use.

I am running a cam with much less duration than you, with iron heads, and I still run on pump gas with over 10.5:1 compression (static).