How To Lap Valves Restore An Old Car
Shop: Valve Grinding Compound. The threeounce Permatex 80037 is a mixture of four grits; 120, 150, 180, and 220. The compound starts off as 120 grit and as you work it, ends up as 220 grit. Although some seats may need two or three times of lapping, it is not necessary or good to overlap the valves.