Cylinder Head Assembly: Description and Operation

Cylinder Head And Gasket:

The cylinder heads of the M73 are identical to the M70 engine in the areas of:
- Cross flow design
- Die cast aluminum
- Asymmetrical combustion chamber
- Single overhead camshaft/two valves per cylinder
- Hydraulic valve compensators
- Interchangeable for use on either cylinder bank.

One difference is in the area of the camshaft bearing support. The camshaft diameter is reduced and requires reduced diameter supports to match the journal size of the new cams.

Cylinder Head And Gasket:

The M5.2 control modules monitor engine combustion knock The knock sensors are mounted on the cylinder heads. The M73 cylinder block design does not offer sufficient area in the valley to accommodate the knock sensors as on the M50 engine.

Each cylinder head has two additional cast bosses located on the intake side. Like the M70 engine, the cylinder head gaskets are not interchangeable. Coolant passage cut outs in the gaskets are unique from one bank to the other. Note the correct gasket by the "TOP" and "FRONT" markings on each gasket.