Dynamic compression
 

How many engine builders really look at dynamic compression, when building an engine to run on pump gas, I want to use all the compression I can without getting knock,Ive used the calculators online, and Camshaft #s can really make a difference here with ABDC #s, how important is dynamic when building around a cam ? compression can change quite a bit from one cam to another..I`ve heard If I stay in the 7.75 to 8.0 to 1 range, this is best, so if I go with 10-1 static, cam selection gets tuff, or do I find a Cam and build the compression to match it ???

Wow... no takers ? lol. I guess no one uses "Dynamic" ?

The guys that know all the ins and outs of adjusting the compression as per the cam openings and overlaps are not going to freely give advise. I wish i knew more on this subject as well.

You might try Yellowbullet

Very difficult to measure, as even advancing / retarding the cam timing makes big changes in dynamic compression.

What we are talking about is the "capture" of the compression and the efficiency that the pistions movement has on drawing in the charge and expelling the spent gasses. Every aspect has a part in the process, timing, rod length, octane, plug heat range, intake plentum size, runner size, header size and length, etc.

Dynamic
 

Since you mentioned cam phasing, you may be able to select the optimum intake lobe centerline, in an asembled engine, by finding the highest cranking compression of different positions.

couldnt that be done on a calculator ? or not ? lol

http://www.yellowbullet.com/forum/sh...d.php?t=287013

Ignore the ranting of a lunatic over there.

LMFAO :lol: :lol: ol~ Ed is a trip

Well I'm not even gonna try to give an answer and show just how stupid I am. All I could do is call my motor builder (SVRE) and ask him. I'm sure he'd rattle off what you need to know or how to figure it, but I'd just get it all messed up by the time I tried to repeat it.