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INSPECTION Inspect all surfaces with a straightedge if there is any reason to suspect leakage. If out-of-flatness 0.00075mm/mm (0.0001in./in.) times the span length in any direction, either replace head or FOR EXAMPLE:—A 305 mm (12 in.) span is 0.102 mm (0.004 in.) out-of-flat. The allowable out-of- The cylinder head surface finish should be 1.78-3.00 microns (70-125 microinches). Inspect push rods. Replace worn or bent rods. INSTALLATION The alloy cast iron cylinder heads (Fig. 8) are held in place by eight bolts. The spark plugs are located (1) Position the new cylinder head gaskets onto the cylinder block. (2) Position the cylinder heads onto head gaskets and cylinder block. (3) Starting at top center, tighten all cylinder head bolts, in sequence, to 68 N·m (50 ft. lbs.) torque (Fig. CAUTION: When tightening the rocker arm bolts, be (4) Install push rods and rocker arm assemblies in their original positions. Tighten the bolts to 28 N·m (5) Install the intake manifold (Refer to 9 - ENGINE/MANIFOLDS/INTAKE MANIFOLD - INSTALLATION) and throttle body assembly. (6) Install exhaust manifolds (Refer to 9 - ENGINE/MANIFOLDS/EXHAUST MANIFOLD - INSTALLATION). (7) Adjust spark plugs to specifications. Install the plugs and tighten to 41 N·m (30 ft. lbs.) torque. (8) Install coil wires. intake manifold. (12) Connect the heater hoses and bypass hose. equipped, the speed control and transmission kick- (15) Install the fuel supply line. (Refer to 7 - COOLING/ACCESSORY DRIVE/DRIVE - INSTALLATION). Tighten generator mounting bolt to 41 N·m (30 ft. lbs.) torque. (17) Install the intake manifold-to-generator bracket support rod. Tighten the bolts. (18) Install cylinder head covers. (Refer to 9 - ENGINE/CYLINDER HEAD/CYLINDER HEAD COVER(S) - INSTALLATION). (19) Install closed crankcase ventilation system. and air cleaner. (22) Install the heat shields. Tighten the bolts to 41 N·m (30 ft. lbs.) torque. (23) Fill cooling system (Refer to 7 - COOLING - STANDARD PROCEDURE). (24) Connect the battery negative cable. CYLINDER HEAD COVER(S) DESCRIPTION—CYLINDER HEAD COVER The cylinder head cover gasket (Fig. 9) is a steel- backed silicone gasket, designed for long life usage. REMOVAL A steel-backed silicone gasket is used with the cyl- inder head cover (Fig. 10). This gasket can be used (1) Disconnect the negative cable from the battery. oration control system from cylinder head cover. (3) Remove cylinder head cover bolts, cover and gasket. The gasket may be used again. CLEANING Clean cylinder head cover gasket surface. Fig. 8 Cylinder Head Bolt -Tightening Sequence 9 - 84 ENGINE 3.9L AN CYLINDER HEAD (Continued) |