Double check my engine builder please 340 stroke

nm9stheham said
Unfortunately, this program calculates DCR in a very different way, one that looks to be totally unrealistic and unusable. It computes the effective stroke as if the intake valve is completely closed at .050" lobe lift; that is OK for anyone thinks the valve is effectively sealed at a valve lift of .075". (If so, we won't ever have to worry about valve leaks again LOL.) This program also computes a 'DCR at valve lash' which is closer to the numbers that normally get discussed as DCR.

That is always a squishy aspect of DCR computations... at what angle is the intake valve effectively closed and the cylinder pressure starts to build. IMHO this Pipemax program gives an unusable DCR answer; it works the DCR at an intake closing of 43* ABDC. Others use 15 degrees after the .050" point on the intake lobe, or 58* in this case. And then the one I use takes it at the 'advertised' closing point, or 76* in this case.

I'm sure Larry Meaux would be interested to hear how it's incorrect, not to mention all the professional builders that use it for reference.
The problem with basing your whole cam selection on DCR is what I see as "squishy". I've seen more than a few threads talking about how people are adjusting cam timing for this magical 76° closing point, regardless of the combination.
Again I ask @ what RPM are you calculating DCR? Does the induction system operate at the same VE throughout the RPM range? Does cylinder pressure remain constant from 800-6000 rpm? There is a reason it's called Dynamic Compression.