TM 10-4320-310-146-2.REPAIR CYLINDER HEAD AND VALVE ASSEMBLY (Continued)5The cylinder contact surface of the cylinder head can be repaired by machining. Remove up to a maximum of0.0196 inch (0.5 mm) of metal provided the minimum valve recession is maintained.6Replace any valves that show head warping, burning, or other damage.7Replace valves that have seriously scratched or scuffed stems, or pitted, ridged, or cracked tulips, faces, or heads.8Replace valves that have a valve head diameter of less than 1.200 inch (30.5 mm).9Remove slight scratches or scuff marks.10If the cylinder head valve seats were recut, lap the valves by using valve reseating tool and 600 grit lapping andgrinding compound.The valve recession must not be less than 0.018 inch (0.45 mm), otherwisevalve head may touch piston.11After lapping valves, check valve recession.The valve recession shall be a maximum of 0.036 inch (0.90 mm) and a minimum of 0.018 inch (0.45 mm).TEST:1Insert valve (1) into cylinder head (2).2Install cap (3) over valve (1) stem.3Install washer (4) on cap (3).4Install spring (5) on washer (4).5Insert cup (6) into spring (5).6Install two collet halves (7) into cup (6) and overvalve (1) stem.7Press down on collet halves (7) and cup (6) untilspring (5) compress and collet halves (7) are lockedin slot in valve (1) stem.6-4
Integrated Publishing, Inc. - A (SDVOSB) Service Disabled Veteran Owned Small Business