Quote Originally Posted by grifo7
Just been reading some recent stuff on compression ratios, heads etc, and thought I would like to double-check cr on my combo.
I have a 454 .030" over (460 cu in), with Edelbrock Performer RPM-0 aluminum heads. These are quoted as having 110cc chambers.
We fitted TRW L2399-30 pistons which apparently are for open-chamber heads and have a .095 (height in inches?) dome. CR with 118cc heads is estimated at 9.52. Composition gaskets were used.
What cc's about would these domes displace??
As the pistons were designed for 118cc heads, would they have had to do any milling on the piston tops to fit the Edelbrocks?
Shop estimated about 9.8:1 - does that sound about right?
Sorry for so many questions, but if the cr works out less I may shelve my plans to fit a slightly bigger cam.

Thanks guys,
Chris
I found a chart on Flatlander's that gives the following c.r.'s ......
with 100.9 chamber 10.23
with 106.9 chamber 9.71
with 109.4 chamber 9.52
with 116.9 chamber 8.98
with 119.0 chamber 8.84

So it looks like 110 chambers should yield about 9.50:1

The problem with guessing like this is that you have no idea what deck height or gasket thickness Flatlanders used to attain these figures and you have no idea of the deck height and gasket thickness used in your motor. But for all practical purposes, I'd think 9.5 would be real close. I don't think you'd have to do any surgery to the pistons or chambers, the dome is only 0.095" tall.