I have my heads off my engine and since i know a little more about engines than i did when i rebuilt my motor a few years ago, i decided to measure how far my pistons are in the hole so i could more closely calculate my compression ratio. I bought a new handy dandy deck bridge and dial indicator. So i measure on the bottom of the piston and come up with .020, put it on the top and i get .008. Big difference. I get to looking closer at the pistons and realize i can see the rings between the piston and bore. I can move the pistons in the bores. I don't believe this is normal right?
I grab a feeler gauge and can stick a .020 blade between the piston and bore. This is a feeler gauge with the blades about 1/2" wide. Holy crap, thats not right. If piston to wall is suppose to be .007, is that total or per side. I assume its total, bore is .007 larger than piston right? I guess that explains why the piston rocks so much when i was measure deck height right?
Engine runs great, i did a leakdown a while back and it was a little high, i think it was 20-30%.
Pistons i have are TRW L2323 in a 455.
Mental note, find a new machine shop.