This is great information, thanks for posting all

A bit of conflict, which I am not apposed to as it gets one thinking. We have the school of put the contact patch very close to the middle. Another philosophy of running the patch out to the perimeter, making the engine think the valve is larger and fostering better flow. Then the motorcycle making more horsepower due to its valves sitting up in the head which would put the patch in toward the stem. I think it is per case, and a flow bench would take some of the guessing out of this. I am building a 3.6 with 51.5mm I valves. Was thinking that I would need to enlarge the seats as well, feeling that enlarging the valve with the same hole size accomplished nothing. Was told that the larger valve head helped flare the charge in a larger more even pattern. My thought is to put a 15* cut on the inside. That would begin to unshield the the valve. Don't know, but damn the torpedos. Bob