The Mercedes D.II was a six-cylinder, SOHC valvetrain liquid-cooled inline aircraft engine built by Daimler during the early stages of World War I.

Producing about 110 to 120 hp, it was at the low-end of the power range of contemporary engines, and was generally outperformed by rotaries whose power-to-weight ratio tended to be much better.

This arrangement allowed for a much smaller "sump" on the bottom of the crankcase, reducing the overall size of the engine, although in the case of the D.II it was not nearly as much as the Austro-Daimler.

For instance, the D.II featured a single overhead cam, powered by a shaft leading up from the crankshaft at the rear of the engine, whereas the Austro-Daimler had a more conventional valvetrain using pushrods driven from the crankcase.

Deutsche Museum in Munich has one example on display, this is a cutaway model that was created by Daimler [2] Data from Albatros D.I-D.II [1] Comparable engines Related lists