Mercedes D.II
| D.II | |
|---|---|
| D II engine at the Deutsches Technikmuseum Berlin | |
| Type | Inline piston engine | 
| National origin | Germany | 
| Manufacturer | Mercedes | 
| Developed from | Mercedes D.I | 
| Developed into | Mercedes D.III | 
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. It also had stiff competition from the Ferdinand Porsche-designed 120 hp Austro-Daimler 6. The D.II was produced only briefly as a result, but its design formed the basis for the later Mercedes D.III which saw widespread use throughout the war.