Valve Grinding | Hot Rod Forum
· Grind a 45 seat, top it with a quick 30 degree top angle. Drop a ground valve into the guide/seat. determine where your upper seat hits the valve, Use bluing, or as I do, just tap the valve into the seat and read the contact mark. 30 degree stone will lower/narrow seat contact on valve. 60 will raise/narrow the seat from the bottom.