Quote Originally Posted by brian617 View Post
I'm missing something then. I assumed that 100% VE was each engines particular ability to move the maximum about of air volume for its given combination of parts. 100% being the most air that engine could pump regardless of the actual volume of air. If that's wrong please explain.
VE is the ratio of the amount of air an engine actually passes divided by its displacement. A 4-cycle engine fills and empties its cylinder(s) once every two revolutions. If a 350 CI engine passes 350 CI of air every two revolutions it is achieving 100% VE if it only passes 315 CI it is achieving 90% VE. 385 CI is 110% VE.