There is nothing magic about 28″ water. Famed engine builder Smokey Yunick picked this pressure (about 1 psi) many years ago (probably in the 1960s) as what he thought was reasonable, and it stuck. It is now the industry standard.
Tag Archives: volumetric efficiency
More to Heads than just CFM Flow
Recently a well known racing head porter asked for some graphics (pictures) for an article on head port design. His article dealt with there is more to a head’s performance potential than just CFM flow numbers.
Better than Perfect
When we think something is 100%, we typically think it is the best it can be, that is perfect. One way of rating an engine’s breathing ability is called Volumetric Efficiency.