68cc chamber AFR heads and domed pistons

350camaro · 01-24-2003, 02:45 PM

I am trying to find out if any one else is using domed pistons with the 68cc chamber AFR heads, and what pistons they used and if the pistons or combustion chamber needed to be modified.
When I built mine I ended up using the Keith Black hyperutectic KB-119 with a 0.1 dome 1970 LT1 replacement piston. I had to remove a slight amount of material from the combustion chamber on the intake side, I am sure it was less than 0.5cc's.

71roadster · 01-24-2003, 03:09 PM

I was going to use the kb122 with a 7cc dish and the 68 cc head, but that made the compression too low. So I went with the kb123 with a 3.25 cc dome and the 74cc head. I had the machinist machine the dome down to get a total of 10.3:1 or so total compression. It was cheaper to machine the pistons than it is to mill the heads. I am not quite sure what the exact displacement of the pistons is now, but the dome is only about 1/16 of an inch. I think that is better as a larger dome tends to impede flame travel. I would think a dome piston and a 68cc chamber would raise your compression way hi.

Chris

350camaro · 01-24-2003, 03:37 PM

The KB-119 that is in the motor is only 0.1 inches high, my compression ratio with the 0.015 deck height, the fel-pro 1010 head gasket and 68cc chamber comes out to 10.2:1. The only thing I don't like about the AFR 195's is in order to get a decent compression rato on a 350 you have to use a piston with a small dome or mill the heads. I did not want to mill the heads because then if I decide to try a different intake I would have to get the new intake milled too.