Sure... The valve spends twice as much time at any given point between open and close as it does AT open or close. To put it another way... Pick any point between open (.550) and close (.000), let's say .250. The valve hits the .250 mark in its travel from fully closed to fully open, then again in its travel from fully open to closed. This is why it's important to achieve strong and even flow characteristics across the entire range of valve travel.96stang46 said:i actually found out that @.550 the 96 heads out flow p.i. heads it's from .1 up to .450 the pi heads are stronger..... so shouldn't the old heads have a better peak # (hp) and less average i don't understand can some one explain this please.
Thankyou....Black01GT said:sometimes its not the amount of air thats flowed, but the velocity its flowed at. thats the difference between say...a 65mm TB vs a 75mm TB. the non PI heads might flow more @ peak, but the PI flow with more velocity which helps power production.