Hanshin adds slow four-stroke

Pmax is 142 bar with a BMEP of 21 bar, and a maximum piston speed of 6.36 m/sec. During testing the fuel consumption was measured at 185 g/kWh, and the company says the engine will conform to the IMOÕs NOx code.

The inlet and exhaust valves are hydraulically opened and pneumatically closed. Small recesses in the underside of the top piston ring allow a controlled release of gasses to obtain a more even pressure drop across the ring pack.

The design incorporates a separate cylinder lubrication system (similar to a two-stroke) which uses oil at the rate of 0.68 g/kWh. An ?L-ringÕ (piston cleaning ring) keeps lub oil consumption to 0.95g/kWh.