ARMY TM 9-2815-255-24
AIR FORCE TO 38G1-95-2
MARINE CORPS TM 2815-24/4
Intake valve recess should be 0.024 to 0.044 inch (0.61 to 1.11 mm) with a maximum recess limit of 0.064 inch
(1.63 mm). Exhaust valve recess should be 0.048 to 0.068 inch (1.22 to 1.72 mm) with a maximum recess limit
of 0.089 inch (2.26 mm).
If measurement exceeds maximum limit, install either new valves or inserts, or both to obtain proper valve
recess. Grind valve seat inserts as required, refer to paragraph 3-34.4.
Make preliminary inspection of cylinder head and valve assembly during disassembly, looking for following:
Scored Valve Stems
Burned, Pitted, or Worn Valves and Seats
Loose Valve Seat Inserts
Defective Valve Rotators
Worn Valve Guides
Cracked Cylinder Head
Ensure each end of cylinder head is supported on blocks of wood to prevent. serious Injury or
death when using valve spring compressor.
Place solid blocks of wood under each end of cylinder head (2, FIGURE 399).
Do not stand In front of valve springs while compressing them to avoid personal Injury.
Using valve spring compressor, compress valve spring (6) far enough to remove valve spring locks (4).
Release spring (6) tension and remove valve rotator (5) and valve spring (6).
Remove valve (7 or 8) from cylinder head.
Identify all parts for correct reassembly. Use a valve board or other suitable means of keeping
valves in order.
Remove valve stem seal (9) from valve guide tower.
Repeat steps a through d for remaining seven valves (7 and 8).
3-34.4. Inspection and Measure.