Milling of a 810 casing W-2 head

I should mention too, that it was explained to me that it is not the quench pad side that hurts the flow. It's opposite side of the chamber pad. A closed chamber has a very abrupt curvature there that kind shrouds the valve. The open chamber on this same side has a nice gradual curvature that allow the air to get by the valve better. At least that's according to Ryan J. That's also part of the difference in the two Indy heads.