I have 4.382 diameter KB Hyper pistons in my 452 I'm building. The issue started when 3 of the pistons wouldn't fit in the hole. It turns out that the skirt on one was 4.394 while the ring area was 4.382 like it was supposed to be. On two of the others, the skirt was 4.388.
Luckally, that large diameter was on the first piston that tried to go in.
This got me thinking, gee, what if this piston had been machined .002 large instead of .012 large? I wouldn't have noticed. I bet no one would have noticed. It would have installed in the block, and fine ran too. That is, until one day I ran it a little longer and harder than normal. The piston would have then sized in the bore, and shattered in a million pieces.
Is this the real reason why some people have issues with the hyper pistons while millions of others don't?
Anyway, I called summit racing (where I bought them), and they sent a truck and replaced the pistons ASAP. Summit has my business for a long time.
