RESURFACING

Cylinder Head Flatness

When the cylinder head is removed, check the flatness of the cylinder head gasket surfaces.

1. Place a straightedge across the gasket surface of the cylinder head. Using feeler gauges, determine the clearance at the center of the straightedge.
2. If warpage exceeds 0.08mm (0.0031 in.) in a 152mm (5.98 in.) span, or 0.15mm (0.0059 in.) (0.20mm [0.00787 in.] for the diesel) over the total length, the cylinder head must be resurfaced.
3. If necessary to refinish the cylinder head gasket surface, do not plane or grind off more than 0.25mm (0.0098 in.) (0.05mm [0.00197 in.] for the diesel) from the original gasket surface.

   NOTE: When milling the cylinder heads of V6 engines, the intake manifold mounting position is altered, and must be corrected by milling the manifold flange a proportionate amount. Consult an experienced machinist about this.