Hey Curt, most valve bowl cutting today is done with a 85-90% size of the valve that is used. So if you are using a 1.94 intake valve, you would cut the bowl from 1.649"-1.746" . I would use a 3/4" ball mill to just touch where it meets the roof, and let that rad blend the pocket walls and roof. Heres a G13 to do it. G13 Z-x.xxx Dxx I.873 F5. You just need to add the Z depth to the actual amount of depth you need, and put the appropriate D# in it as well to match your tool #. Your X and Y would be the valve centerline. You can kinda' see how the thinking has changed since the 50's as far as bowl cutting goes. But the 85-90% rule of thumb is what all race stuff is today. That is the direction im heading, if you want to go ahead and do a test run with your head,it might reveal something. Also, I had planned to replace the guides, since a G13 starts at the XY centerline, adjust your feed so you don't crash your end mill into it.
