TM-9-2815-202-34 Technical Manual for 8V71T Engines for M109 Howitzer Download
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TM9-2815-202-34 (5) Valve inserts Inspect valve inserts for excessive wear, pitting, cracking, or improper seat angle. Replace inserts as follows: (a) (b) (c) Place cylinder head on wood blocks with bottom side up. Using valve seat insert remover (82), remove valve seat insert (83). Clean valve seat insert counterbore in cylinder head and inspect for concentricity, flatness, and cracks. NOTE Insert counterbore has a diameter of 1.2600 to 1.2610 inches and a depth of 0.3380 to 0.3520 inch. Counterbores must be concentric with valve guides within 0.003 inch total indicator reading. (d) Immerse cylinder head in water heated to 180 o F-200 o F (82°C-93 o C) for 30 minutes or cool insert with liquid nitrogen. NOTE Install insert in cylinder head while head is still hot and insert is at room temperature or when insert is chilled and head is at room temperature. (e) Place cylinder head on a bench with bottom side up. Place insert in (f) counterbore with valve seat side facing up. Using valve seat insert installer (84), drive insert in place until it seats solidly in cylinder head. Change 1 5-47