The question in my original post was in fact related to spring losses only. It was a topic that I had heard from some very respected engine builders through the years, and quite frankly took their word at face value (I know, question everything).
I was looking at a desmondronic valve train...
I've seen various claims of valve spring power consumption of 20-35% of gross power for 2-valve pushrod engines. In our own application, inline 4-cylinder w/peak horsepower of 335@6400RPM, I can calculate approximately 100HP used to open the valves. This was based on the work done from the cam...
