Speedmaster head hypothetical

I'm going to bet when you draw it out and can see the relationship between the valve surface and seat/transition and how that small change altered the venturi, you'll have an aha moment.

It really shouldn't come as a surprise, even though it does, how minute changes alter everything. I mean, think about it. What happens when you put your hand in a 300 fps air stream and turn it slightly. I realize it's not the same thing but the point being we're talking about some really fast moving air and fuel being carried by that air. The things you are showing/discovering are the tip of the ice burg and I'm digesting as much as I can.