Gsoleski

I would like to know how to find what the CC of this dished piston is. Says the dish is 0.080in deep and 3.020in in diameter. Can anyone help me out here? I did try contacting the manufacturer but they didn't tell me anything.

http://www.summitracing.com/parts/slp-h815acp30

Brando5641

iTrader: (-1)

You will have to measure it with fluid. If it was a perfect square dish we could figure it out but with the curves it is just about impossible.

FtrSpeedy

You could be looking at -28cc, just a guess. Shallow dishs are around -20 and 4valve reliefs around -8cc
Ive never seen a dished with valve reliefs though.

Damon

Those are basically stock replacements for Vortec truck motors. I will assume they have about the same dish volume as stock pistons, which would be about 12cc.

Note they have a 1.550" pin height. Stock height would be 1.560. Which means they would be sitting about .035" in the hole at TDC on an undecked block (.010" deeper than stock). Just thought I'd mention that. It affects your compression ratio just like the dish cc does.

sofakingdom

iTrader: (1)

Very easy to calculate, given those dimensions...

The area of the dome is (3.20" ÷ 2)² × pi, or about 8.04 sq in. Its volume is therefore about .643 cu in. This converts to about 10.5 cc. If you leave out the .5 to account for the curved edges, and add about 5cc to account for the valve reliefs and the bevel around the edge, then it's around 15cc.

That # pretty much passes the smell test of what those of us who have measured typical stock shallow-dish pistons have come up with over the years.

Given the size of the other errors in any of this exercise taken as a whole - chamber volumes can EASILY vary 4cc, and deck height variations can be 3 times that - it's PLENTY accurate enough for most uses.

Gsoleski

thanks that's exactly what I was looking for! and damon thanks for letting me know, I never even noticed that