I am having my valves and seats ground in my Kohler K532 and Im not sure about the whole grinding lapping thing. I have read in different places that you must lap the valves after a new grind but the machinist said you should never lap the valves after a grind because the grind is as precise as you can get and youll just mess it up by lapping. So when I get it back do lap or not?
I was always under the impression that if a valve was "machine ground" that was as precise as it gets. Lapping was done more for checking a valve/seat contact surface, and or cleaning process. I hope this helps!
I think it depends on who/what equipment is used.My local small engine guy does my valves in his little workshop with his old stone setup and laps them in to get the contact area correct.the machine shop that does my race engines for the cars machine cuts the seats in their cnc clean room environment and they say its right on.my .02 Later Steve!!