Pistons

Piston:

The aluminum alloy pistons of the M73 are coated with a very thin (0.1 mm) metal film. Like the M70, the pistons are different for the left and right cylinder banks to compensate for the wrist pin offset and the asymmetrical combustion chamber.

The combustion bowl on the top of the piston has been redesigned to spread the initial combustion forces evenly across the top of the piston.

The new pistons have a thicker fire land. Even though the compression ratio has increased, valve notches are not required due to a reduction in the intake/exhaust valve overlap.

Piston Specifications:
- Compression Ratio = 10.0:1
- Piston Diameter = 85+mm