11 12 591 Installing valve guide Checking valve seat for wear • Apply engineer’s blue or a similar product to the valve seat rings. • Install correct valve and rotate, applying slight pressure. 1 F110151 A • Heat the cylinder head to 100 °C (212 °F). • Using driving-in tool, BMW No. 11 0 571 , drive valve guide (1) into the cylinder head until valve guide projection is as specified. F110160 Projection: Inlet........................... 9.8...10.2 mm (0.39...0.40 in) Exhaust ..................... 9.8...10.2 mm (0.39...0.40 in) • Check valve seat width “ A ” and contact pattern for wear. Wear limits for valve seat width “A”: Inlet valve ......................................
1.6 mm (0.03 in) Exhaust valve .............................. 2.2 mm (0.087 in) L Note: Only use thread-cutting oil to lubricate the reaming tool. Only rotate reaming tool in the cutting direction - never in the opposite direction! • Once the wear limit of the seat width has been reached, or the contact pattern is no longer per- fect, the seat can be remachined. • If necessary, remachine valve seat with valve seat turning tool (2). Valve seat width “B”: Inlet valve ....................................................1.2 mm Exhaust valve ..............................................1.4 mm 11.31 Withdraw reaming tool at regular intervals for clean- ing:
always rotate in cutting direction when doing so! • Ream out valve guide with 5H7 reaming tool. 2 E110540