Anyone one here ever run into this?? Diamond custom pistons, piston card calls for 1/16 x 1/16 x 3/32 rings, 4.600 bore. I got Mahle rings, correct size and fitted them to the bore. When I try to load the piston into the cylinder, the piston gets stuck in the ring compressor (tapered sleeve, correct size). After getting the piston assembly unstuck (without damaging anything!!), and doing a lot of investigating, I find that the top ring is bottoming out in the piston. Everything else is fine. I go retrieve the old rings that came off these pistons and find that width of the old ring is .169" (not top to bottom, but from the face of the ring to the inside diameter). The new top ring is .194", and the ring gap in the cyl bore is correct at .021", but when it is on the piston and "bottomed out", the gap is in excess of .030" and the diameter of the ring at that point is in excess of 4.602".
I have the actual work order from when the pistons were made and it list the rings as 4.600b 1/16ap x 1/16nap x 3/16std.
At this point I'm standing here going WTH?? Any suggestions other than calling Diamond on Monday?

Thanks, Brian

Last edited by '72CudaRacer; 03/05/18 09:29 PM.