Paul. Your question is a good start for a new thread.PF Arcand (6/30/2010)
John: Possibly this has been covered before but I've not seen it. If your new heads are installed on a 292 or 312 with stock pistons (lets assume the block is not over bored more than 0.020 thousands) in a non decked block, what will the approximate compression ratios be? Thanks.9.09:1 static compression ratio for a 292 with 0.020” overbore and pistons in the hole 0.025” with the Mummert aluminum heads (60cc). G heads at 69cc’s on the same engine will have a cr of 8.22:1 while the 113 heads at 72cc’s will lower the cr even more to 7.97:1.
9.65:1 static compression ratio for a 312 with 0.020” overbore and pistons in the hole 0.025” with the Mummert aluminum heads (60cc). G heads at 69cc’s on the same engine will have a cr of 8.72:1 while the 113 heads at 72cc’s will lower the cr even more to 8.45:1.
Lorena, Texas (South of Waco)