General Cylinder Head Flow Numbers discussion

[Glenn Briglio]

Originally Posted by SSDiv6

I should have explained better. Optimize the velocity, and like Ralph Powell said, go at least 0.100" ~ 0.150" past your maximum lift and you want a quiet port.

Seen too many heads with big flow numbers and low velocity that do not make power. Your valve job angles are also critical and different for each head manufacturer.

The reason why you want to have a good flow past your maximum lift is because you can make more power by doing a controlled loft of the valve past your maximum allowed lift. The cam lobe is designed to toss the lifter and increase valve lift to make more power while still checking legal during a static lift inspection.

So how much valve loft are we talking about?