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TM-9-2815-202-34 Technical Manual for 8V71T Engines for M109 Howitzer Download

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TM9-2815-202-34 4-38. CYLINDER HEAD REPAIR (6) Valve seat insert grinding (Cont) Use a valve seat grinder (84) and valve seat grinder adapter kit to grind inserts. Grind valve inserts as follows: CAUTION Do not permit grinding wheel to contact cylinder head when grinding insert. If an insert has been ground until grinding wheel contacts cylinder head, then install new insert. (a) Apply 31-degree grinding wheel on valve seat insert. (b) Grind throat of insert using 60-degree grinding wheel. (c) Grind top surface of insert with 15degree grinding wheel to narrow seat width to dimensions shown in figure. The 31-degree face (85) of insert maybe adjusted relative to center of valve face (86) with 15 and 60-degree grinding wheels. NOTE Maximum amount exhaust valve should protrude beyond cylinder head and still maintain proper piston to valve clearance is shown. Grinding will reduce thickness of valve seat insert and cause valve to recede into cylinder head. Replace valve seat insert if valve recedes beyond limits. 4-196