jerry34208-
Yes pretty much..
The 'pressure wave' as you termed it, is a result of a combustion event. As it happenss you have expanded spent gases being forced out the port & at the same time the cam(s) have overlap (meaning that while exhaust cam is closing, intake is already opening too.aka Overlap.. that momentararily (depending on cam type) tries to draw spent gases back in. This is called reversion..
The smaller ports = faster is based on a Scientist A. Bernoulli from late 1800's who discovered the benefits of a venturi (or kinda like a funnel)...But for HD I don't believe that extra heat to that degree was expected.. That's another reason HD added piston crown oilers to the undersides of TC pistons to help quench the extreme heat..
Here's some examples:
http://en.wikipedia.org/wiki/Venturi_effect
