TM-9-2815-202-34 Technical Manual for 8V71T Engines for M109 Howitzer Download
Page 301 of 670
TM9-2815-202-34 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 -200 o F (82°-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) (9 (9) Place cylinder head on a bench with bottom side up. Place insert in counterbore with valve seat side facing up. Using insert installer (82), drive insert in place until it seats solidly in cylinder head. Check exhaust valve seat inserts for concentricity in relation to valve guides using insert runout gage (83). NOTE Exhaust valve seat inserts are prefinished. Only check for concentricity after installation. Grind insert only if runout exceeds 0.002 inch. 4-195