Originally Posted by dre1984
i have a 96~99 bbc 454 and the pistons are two valve relief and the number on top is 12563092 and i am trying to find the compression on them any help will be helpful
Finding static compression ratio requires knowing 5 different values.
1. cylinder volume in cc's
2. chamber volume in cc's
3. piston deck height volume in cc's
4. piston crown volume in cc's
5. head gasket volume in cc's
If you want it done right, pull a head and start measuring.
You add all the values together, then add all the values together with the exception of the cylinder volume. Then you divide the larger total by the smaller total. That is your static compression ratio.
Nobody said this stuff is easy. At least, nobody who has done it before.