Compression ratio??

[markrr]

How is the compression ratio of a 440 determined? Can it be figured out with the motor all assembled?

 

[bigmanjbmopar]

http://www.csgnetwork.com/compcalc.html




http://www.allpar.com/mopar/383.html

 

[Kern Dog]

How is the compression ratio of a 440 determined? Can it be figured out with the motor all assembled?

Of course. You just need the exact specs of the engine to get there.
You need to know the following: Cylinder bore size, Stroke, piston dish or dome amount, head gasket thickness and the distance below deck the piston is at TDC.
If the CR is needed just for bragging rights, you could just do a compression test. A car with a stock idle and under 10 to 1 usually has less than 170 psi of cranking compression.

 

[Meep-Meep]

Not accurately. Cranking compression will give some insight but that also takes the cam into account. I'm in the same boat with a mystery 426 hemi. 225 PSI cranking, idles like a 318 and pings on pump gas.

 

[bigaadams]

actually the compression ratio is still calculated the same with the big super cam...the question had nothing to do with effective CR due to cam size..