Cylinder Head Assembly: Description and Operation

General Repair Information

• If a replacement cylinder head is installed, several contact surfaces between the support elements, roller cam follower and cam lubricating surfaces of the camshaft must be lubricated before installing the cylinder head cover.

• The plastic protectors installed to protect the open valves must only be removed immediately before installing the cylinder head.

• Replace the cylinder head bolts.

• When replacing the cylinder head or cylinder head gasket, the coolant must be replaced.

• Cylinder heads with cracks between the valve seats, or between the valve seat and the spark plug threads, can continue to be used without reducing the service life, as long as the cracks have a max. width of 0.3 mm, or only the first 4 threads of the spark plug threads are cracked.

• The cylinder head and guide frame may only be replaced together.

• Do not regrind the valve seats in the cylinder head, only lapping the valves is permitted.

• After installing the camshafts, the engine may not be started for approximately 30 minutes. The hydraulic adjusting elements must seat themselves (otherwise the valves will seat themselves on the pistons).

• After working on the valvetrain and lifters, carefully rotate the crankshaft by hand at least 2 full revolutions before starting to be sure that valves do not strike the pistons.

• Always replace gaskets and seals.