Lapping your own valves

OK, I was avoiding this question for multiple reasons but here goes:

1: To lap valves the head of the valve must be shiny clean or the suction cup will not grip.

2: You must have a way to thoroughly clean the seat/port (safety clean tank) or the abrasive compound will destroy your engine.

3: Forget about performance as the valve/seat area and how it mates has a tremendous impact on flow.

4: If the seats can catch a fingernail on the surface pits, they need to be cut.

4: If you're still interested, you can lap using the compound found at any NAPA store. Just a drop at three or four spaces around the seat area of the valve will do.

5: Use your suction cup on a slow speed drill and go forward/reverse pulling the valve up at 5 second intervals. You'll immediately see where the problem is in the grind pattern.