Well I think I finaly have managed to arrive at the largest pistons that will fit under the heads of the V7 Sport.
At first I used the stock pistons. Hemi baby! Some power but I was RACING and needed BIG COMPRESSION.
So CP Pistons made me their largest billett pistons to fit stock bore. They started off as 12:1 but flycutting for the big valve and the sinking of both valves into the heads reduced the compression considerably. Cool pistons though.
Turns out the demensions I gave CP were for the stock heads and the "hot" heads caused low pressures. ugh.
So back to CP, and with help from Terry Stewart from Shaker Products, we used the "hot" heads for the spec. we came up with this:
The previous forged pistons were as tall as forged pistons come. If I wanted to blow the heads off I needed to have pistons cut from billett. This is what was done. The flycutting reduced the max compression, of course, but all of the combustion area should now be filled with piston. We are looking at minimal clearance to the head. I'll need to clay this thing very carefully and adjust with gaskets. The cylinders have wire o-rings for copper gaskets and I have every size available from Gaskets Unlimited.
If this doesnt get the pressure I'm looking for I think I'll move on to Tiddley Winks.
Alex
At first I used the stock pistons. Hemi baby! Some power but I was RACING and needed BIG COMPRESSION.
So CP Pistons made me their largest billett pistons to fit stock bore. They started off as 12:1 but flycutting for the big valve and the sinking of both valves into the heads reduced the compression considerably. Cool pistons though.
Turns out the demensions I gave CP were for the stock heads and the "hot" heads caused low pressures. ugh.
So back to CP, and with help from Terry Stewart from Shaker Products, we used the "hot" heads for the spec. we came up with this:
The previous forged pistons were as tall as forged pistons come. If I wanted to blow the heads off I needed to have pistons cut from billett. This is what was done. The flycutting reduced the max compression, of course, but all of the combustion area should now be filled with piston. We are looking at minimal clearance to the head. I'll need to clay this thing very carefully and adjust with gaskets. The cylinders have wire o-rings for copper gaskets and I have every size available from Gaskets Unlimited.
If this doesnt get the pressure I'm looking for I think I'll move on to Tiddley Winks.
Alex