Nissan Micra Cylinder Head Inspection: Valve Inserts, Cam Journal & Runout Specs

This page (EM-13) from a factory service manual covers cylinder head inspection procedures, continuing an 'Inspection (Cont'd)' section. It has two main topics. First, VALVE INSERTS: it instructs checking valve inserts for pitting at the valve contact surface, and reseating or replacing them if excessively worn. It cautions to check valve and valve guide wear before repairing inserts, and to cut or grind inserts uniformly. A six-step replacement procedure is given: ream the cylinder head recess after removing the insert, heat the cylinder head to 150-160°C (302-320°F), press-fit the insert until seated and caulk at more than 4 points, cut/grind to S.D.S. dimensions, lap with lapping compound, and check contact condition. Second, CAMSHAFT JOURNAL CLEARANCE: the wear limit is 0.15 mm (0.0059 in), with a standard camshaft bore inner diameter of 40.00-40.03 mm (1.5748-1.5760 in) and standard journal outside diameter of 39.95-39.97 mm (1.5728-1.5736 in), measured with a bore gauge and micrometer as illustrated. Finally, CAMSHAFT RUNOUT is specified at a limit of 0.10 mm (0.0039 in) total indicator reading, checked on V-blocks with a dial indicator. Illustration reference codes SEM009A, SEM544, SEM012A, and EM302 appear on the figures.