Grind intake valve seat using a 30° seat grinder, and exhaust valve seat using a 45° seat grinder. Follow tool manufacturers instructions.
Measure valve seat width (E) after grinding.
 – If seat is too wide after grinding, grind lower seat surface (F) using a 70° seat grinder until seat width is close to specifications.
 – Grind upper seat surface (G) using a 15° seat grinder until seat width is narrowed to specifications.
 – If valve seats (H) are ground, measure valve recession and check contact pattern between the seat and valve with bluing dye.
 – Lap valves. (See procedure in this group.)
If valve recession exceeds maximum specifications or seats cannot be reconditioned, replace cylinder head.