Guys
Compression Ratio is based on the total volume in a given cyl. at top dead center it makes no difference how many cyl you have. the following is the total cc s that will give you the compression ratio on a 250 cu in chevy bored .030 over. this includes deck height space, cyl head space, and the thickness of the compressed head gasket minus any piston dome plus any valve relife to get total ccs for compression ratio.
9 to 1 86.85cc
10 to 1 77.20cc
13 to 1 57.90cc
15 to 1 49.63cc
I most likely miss understood the post, and I am not criticizing anyone just making an observation. If I hurt someones feelings I am VERY SORRY as I did not not mean to.
Also Sunoco sold 190 through 260 to anyone. In the old days we used to get some dealers to break the seal on the pump and sell us the straight fuel that the pump mixed with its 190 to make higher grades they called it 280. 280 worked very well in a blown Hemi running 25 psi of boost. I never did know the exact octane rating of 280 it was claimed to be everywhere from 104 to 120 depending who you talked to. They also used a different method of determining the octane rating then, than they do now
Big Bill
