SM Head Modifications on a budget
Since we've been talking flow separation so much this might be a good time to insert this interesting theory. If flow is separating from the short side of the port, what exists in the 'void' created when the air detaches? In Erland Cox's Speed-Talk post 'Chamber Stall', he says that separation actually starts in the combustion chamber and works its way back up the port. In this theory, the 'void' is actually high pressure air from the chamber blowing back up the intake port. Chamber air is at a higher static pressure than the fast moving port air because the combustion chamber air has low velocity. I thought it was thought provoking.