Jim,
In one of his books he says he trained as an aero space engineer. if you want to read a really interesting book, his book on head porting should be on the list.
He argues that measuring all valve lifts at fixed depressions, say 28", is misleading & his arguments for same are very convincing.
IIRC what David V talks about is using a higher pressure drop at low valve lifts and a lower pressure drop at large lifts to better simulate what is actually happening in the port.
And that is some of the theoretical insight that one gets by reading David V books and articles. Is it all practical? That depends upon how comfortable one is with being precise and exacting in their port work. We all know that very good results can be attained with less than perfect execution. And that is fine.
But if your quest for knowledge and information goes beyond that, David V’s port and flow test book will give you port flow ideas to ponder.
