the dynamic compression you can run depends a lot on the combustion chamber design and is beyond my understanding..

With this in mind - your choices are really to use someone elses hard work and go with a proven combination, use someone else hard work to determine an allowable dynamic compression ratio (would require a decent knowledge of one of the many engine building programs) or choose your power output or rev range and get an engine builder or cam company to do the calculations for you..

Or, I'll just go for roughly 10.5 static comp, then go from there. An increase from 9 - 10.5 should work in my favour if I'm using the same heads and cam I have now.

Go for better pistons as you will incur extra expense by milling the heads and ultimately the lower inlet to get it to fit.

Oops, not that you would consider milling the alloy heads that you already have fitted..

BTW scaffy, what cc are the chambers on your trickflows? Assumming you have the standard bore size and stroke, calculate the volume of your cylinder below the deck by pie(3.14) x r2(radius squared) x your stroke. Add about 0.020 to 0.030" x pie(3.14) x r2 for the head gasket. Add both of these together to find your ratio of cylinder volume to compression chamber volume.

My E7s were milled 0.030" and my chambers differed by a few CCs but roughly on my standard bottom end I ended up with about 9.2 to 9.3:1.

Last edited by banarcus on Tue Dec 23, 2008 9:52 am, edited 1 time in total.

Yeah, better pistons would be going in with the 347 rotating assembly