Flow Data from Intake Valve Relocation

I have never flown a port backwards. I’m not saying you are wrong, but I heard Darin Morgan say to fight reversion with velocity and cam timing, not seat angles. I do know this. The steeper top cuts fight reversion both on overlap and the short side reversion that occurs at high intake valve lift.

Seat is 0.050 wide. 65 cut is 0.110. Width of 75 degree cut varies as can be seen with the purple line length. As you can imagine, the undercuts hit much harder on the exhaust valve side than on the cyl wall side. I like the way this leads the air into the combustion chamber.

All cutters are Goodson 3D system. Angles are individual cutters since all this is experimental. It’s just easier that way. I did make a custom cutter for the top cut that is a 40 degree that transitions to a 90 degree with a 4mm radius. This cuts the 40 degree all the way out to the 90 degree at the 4.07 bore circle in one cut.