Jul 24, 2000 · Using Pat Kelly's calculator your dynamic compression ratio is a little over 7.0:1 with the .039 gaskets and a little over 7.4:1 with the .018 gaskets, which is basically saying your cam is too big for your combo, or your compression is too low for that cam. You want to shoot for around 8.0 dynamic compression for a street car.

Nov 6, 2024 · I ran 13:1 on 91 octane. It depends on more than just the static compression ratio. If it has tall gears, a manual transmission and high cylinder pressure it could be a problem. Does it have aluminum or cast iron heads? If it has some lower gears like 3.50 or lower and cylinder pressure 160-180, it will be fine. I've run up to 230psi on 91 octane.

Jul 24, 2008 · 307 stock compression ratio Jump to Latest 9.8K views 1 reply 2 participants last post by Z15CAM Jul 24, 2008

Apr 4, 2021 · There's more to it than just static compression ratio. I ran 10.9:1 in my '69 Camaro when it was a daily driver on 91 octane pump gas. The cam had almost 30 degrees more duration at 0.050" than your cam and the stroke was only 3.48", but the ICL was 102 so it cranked 215-230psi on a cold compression test.

Mar 16, 2006 · Yes you can slide by with more compression on with aluminum heads because they do indeed transfer more heat out of the combustion chamber (at a faster rate) than steel heads do. The ultimate point of detonation is determined by air fuel mixture and dynamic compression ratios; assuming there are no preignition sources.

Feb 20, 2002 · Dynamic compression ratio works out to about 7.59:1 for the XE274, and 7.36:1 for the Magnum 280. This is a little bigger difference than I expected, but they are still pretty close. While idle quality will be nearly identical between the two cams (driven by overlap which IS identical), the XE274's smaller intake lobe (dual pattern cams all ...

Mar 9, 2000 · A combination of low LSA and long duration is what you want with high static compression ratio, which is exactly what you did. The OEMs did this in the 60s to support the 12 to 13:1 compression ratio engines they built. A high LSA (112-114 degrees) and long duration would be knock city.-----

Nov 1, 2007 · Higher compression ratios (actually higher cylinder pressures) allow you to get more power out of the engine. However, the fuel becomes the limiting factor. With 93 or 97 octane (at best) you start having problems with pinging and detonation when the compression ratio gets above about 9.5:1 for iron heads and 10:1 for aluminum.

Apr 15, 2008 · My proposal considers future options; such that, .005" + say a .030" (Composite Gasket) = .035 Quench which is optimum and you got another .009" to work with available gaskets plus you can always take more off the head if you ever decide you want more compression pending Piston to Valve clearances. Just my opinion ))

Dec 22, 2020 · If I put a Gen 2 crank into a Gen 1 using Gen 1 rods and pistons, with the stock Gen 1 having a compression of 11:1, how much will the compression ratio increase with the increase of 2mm on the stroke?