SBM Edelbrock/Speedmaster Head Data

Killer6 said
the valve changes from peripheral flow control to an airfoil/aerodynamic wing during the lift cycle...

Just taking a little time to read through this and think about it. Let's discuss this. I think things like this are key to making a port and chamber better.

I agree with the first part of the statement that early in the lift cycle the full perimeter of the valve is flowing well. That starts changing about 350-400 lift. At roughly the 0.25 x valve diameter point (give or take), the majority (but not all) of the flow shoots across the top of the valve. I would like to hear your thoughts on the airfoil/aerodynamic wing part of this statement.

Killer6 said
The valve is partially blocking excess negative pressure from dis-orienting the established directional flow. It's aerodynamics outside-in, but less predictable, & more complicated.

This is the part I really want to discuss. It's my way of thinking that the valve is partially blocking POSITIVE pressure from re-directing the flow. That's what flow separation is. The flow separates from the short side and low velocity (higher pressure) air from inside the chamber pushes up against the high velocity (and low pressure) air stream, choking off part of the flow. Right at the valve seat on the SS air is actually traveling up the port in the opposite direction.