Originally Posted by 454C10
FYI, valve overlap doesn't effect cylinder pressure, as the engine isn't trying to make cylinder pressure during this part of the 4 stroke cycle. The intake closing point is what effects dynamic cylinder pressure (what you would measure on a compressing gage). And a "longer duration cam" will tend to have later intake closing point, the extra overlap is often wrongly accused of reduce pressure as more overlap typically accompanies longer duration cams.
^Agree, thanks for posting this.