I have a set of TRW forged Al pistons installed, and I am putting on my new AFR 195cc heads. I am trying to check valve/piston clearance, and I was wondering if the valve reliefs might not be large enough for the new valves. Do the valve reliefs vary from piston to piston, or is it a standard size?? Thanks.

 

Most off-the-shelf pistons that have reliefs are usually cut to the same depth, so if the angles are relatively the same, the volume would be approximately the same. However, most factory pistons have four reliefs, while many aftermarkets have only two. It would be a good idea to get out the Play Doh and measure to be sure.