5-28 ENGINE TOP END
Marks Stamped on the Cutter
The marks stamped on the back of the cutter [A] represent
60° ........................... Cutter Angle [B]
....................... Cutter Outer Diameter [C]
Repair Operating Procedures
Clean the seat area carefully.
Coat the seat with machinist's dye.
Fit a 45° cutter into the holder and slide it into the valve
Press down lightly on the handle and turn it right or left.
Grind the seating surface only until it is smooth.
Do not grind the seat too much. Overgrinding will
reduce valve clearance by sinking the valve into the
head. If the valve sinks too far into the head, it will
be impossible to adjust the clearance, and the cylin-
der head must be replaced.
Widened Width [A] of engagement by machining with
Ground Volume [B] by 32° cutter
Correct Width [D]
Ground Volume [E] by 55° cutter
Measure the outside diameter [O.D.] of the seating sur-
face with a vernier caliper.
If the outside diameter of the seating surface is too small,
repeat the 45° grind until the diameter is within the spec-
Original Seating Surface [B]
Remove all pittings of flaws from 45° ground surface.
Alter grinding with 45° cutter, apply thin coat of machin-
ist's dye to 45° [A] seating surface. This makes seating
surface distinct and 32° and 55° grinding operation eas-
When the valve guide is replaced, be sure to grind with
45° cutter for centering and good contact.