[screamingchief]

The biggest problem with DCR based theory is that it only truly relates to what is happening when the engine isn't actually running.

Once the engine is actually running, all bets are off, as numerous other dynamics come into play that the DCR calculations cannot even begin to account for.

That's the point that Harold B. is often trying to get across when he dismisses the whole DCR thing as a waste of time.

And I believe that's what Paul (gtofreek) was talking about too.

Cylinder filling dynamics in a running engine are based on far more than just the things that DCR calculations account for, and that includes the IC event too.

So if you need to know what the DCR is for an engine while it's cranking over, then I guess DCR theory tells you everything you need to know.

Though it doesn't tell you much of anything useful beyond that.

DCR wont tell you how much HP a given engine may (or may not) make.

And it wont tell you with any reliable accuracy if you can run on a given octane fuel either...

FWIW

Bret P.