The first successful diesel engine in the history of aviation powerplants.
In 1907, Hugo Junkers patented a multi-fuel engine. The idea did not attract interest at that time. He returned to it in the 1920s, adapting the engine to run on diesel fuel. It was a response to the demand for an economical engine for aircraft capable of performing long-distance flights.
Developed in the early 1930s, the Jumo 205 is a two-stroke compression-ignition engine with 6 cylinders in a vertical inline configuration. Each cylinder contains two opposed pistons driving two crankshafts. Their rotation is transmitted through a gearbox to the propeller shaft.
The Jumo 205 is considered the only successfully operated diesel engine in the 20th-century history of aviation powerplants. It was used, among others, in the Blohm & Voss BV 138 and Dornier Do-26 flying boats.
| Configuration | 6-cylinder 12-piston inline |
| Cooling | liquid |
| Compression ratio | 1:18 |
| Displacement | 16.0 l |
| Power | 800 hp |
