cylinder head and valves
The cylinder head is of cast iron and fastened to the cylinder block with washer faced setscrews. The joint is made with a non-retorque steelcore gasket with soft facings. Each cylinder has two overhead valves and the rocker gear is fitted on top of the cylinder head which has a cast aluminium cover. The valves operate in cast iron guides fitted to the cylinder head and have springs held in position by a hardened steel cap and split collets. Hardened steel valve spring seats are fitted in recesses in the cylinder head. Valve seat inserts are fitted to both valves on all full rate turbocharged engines. A synthetic rubber valve stem oil seal is fitted to the top of each inlet and exhaust valve guide.
Cylinder block and crankcase
The cylinder block is made as one unit from high duty cast iron with an integral crankcase. The sides of the cylinder block extend below the crankshaft centre line to give added strength. The cylinder bores are fitted with dry liners of high duty cast iron, which can be renewed and are a press fit into the cylinder bores. The water jacket extends down the full length of the cylinders and a water space is made between all cylinder bores.
valve rocker assembly
The valves are operated by cold drawn push rods with induction hardened ends, flat faced, large head tappets fitted in the cylinder block and cast iron or forged steel rocker levers. The rockers and valve gear are lubricated by a reduced oil flow mechanism via the camshaft oil feed through internal holes to a hollow hardened steel rocker shaft.
The rocker shaft is supported by cast iron brackets which give support between each pair of valves.Tappet adjustment is effected by hardened,ball ended adjustment screws and locknuts at the pushrod end of the rocker lever.