Cylinder Head Assembly: Description and Operation

Cylinder heads are unique to each cylinder bank and are secured, using deep seated bolts, to the cylinder block. Two hollow dowels align each cylinder head with the cylinder block.
Each cylinder head gasket consists of a silicon beaded composite gasket with metal eyelets for the cylinder bores.
Each cylinder head incorporates dual overhead camshafts operating four valves per cylinder via solid aluminum-alloy valve lifters. A steel shim in the top of each lifter allows adjustment of valve clearances.
Valve head diameter is 31 mm for exhaust and 35 mm for intake, and all valve stems are 5 mm diameter. Valve seats and guides are sintered metal inserts.
Collets, valve collars and spring seats locate the valve springs on the intake and exhaust valves. Valve stem seals are integrated into the spring seats.
Four 14 mm spark plugs are located in a recess on the center-line of each cylinder head.