Just wondering if anyone has had any experience with these? They are the only 83mm pistons i can find. The ad for them says they are relieved for high lift cams, what cams will work with them.
Thanks in advance
The CP pistons are a decent piece. They are roughly 11.7:1, irregardless what they say they are. The dome is 3.5cc's, and they have .185 pockets. I helped them with the 750 pistons, and they just put the same dome on a smaller piston.
This was their original design, and it hits the edges of a KFX chamber.
Later, they nipped the edges off, and it cleared, but they lost a little volume by doing so.
This was the best they could do for me without going to a Keller molded piston, which are nearly 600 bucks a set dead cost. It's a little taller, and the ears are still taken off, but it wasn't much over 12:1.
This is a $600 dollar Keller molded piston
They make a good product if they care to make it. My problem was, I was always treated like I was too small to matter to them, and I found someone that would give me the time and effort I needed to make things better.
A keller mold is just CP's term for digitizing a chamber, and reverse imaging that dome on top of a piston. I designed a chamber, sent it to CP, and they digitized it, and put it in a file for me, and it is only available to me. When I order a piston, it can be designed up to a max, like you see in the last picture, and that's as big as it can get.
It was $176 for each piston just to implement that design. Diamond now does that for much less. Both companies charge a few hundred bucks to do the initial head scan.