The Jumo 205C engine legend runs

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The world’s only series-tested and still running aircraft diesel opposed piston engine was launched for the first time in front of an enthusiastic audience at the Hugo Junkers Museum of Technology in Dessau, Germany, on April 16, 2015, after a long restoration process as part of the 9th Dessau Gas Engine Conference.

The Jumo 205C aircraft engine, built in 1938 at Mitteldeutsche Motorenwerke GmbH and developed by Hugo Junkers, is on loan from the Museum of Technology in Magdeburg.

Our Mr. Möller subjected the Jumo 205C in the WTZ to a fundamental almost two-year restoration, whereby Mr. Möller with his proud 80 years is older than the engine itself. In addition to the restoration of the engine, all the necessary circuits, tanks, an engine frame, and a compressed air starting device were built for later operation. The crowning glory of the assembly was the addition of an original Junkers wooden propeller, which the Hugo Junkers Technical Museum in Dessau was kind enough to provide. Thus, the Jumo 205C became a true aircraft engine again.

The 6-cylinder in-line diesel opposed-piston engine with a maximum output of 600 hp has two crankshafts and operates as a two-stroke reciprocating internal combustion engine in which two pistons in the same cylinder work against each other and share a common combustion chamber in the middle of the cylinder. Two diesel injection pumps and four diesel injectors are assigned to each combustion chamber.

This type of engine is lightweight, compact, has higher power efficiency and consumes about 30% less fuel than conventional aircraft engines. The Jumo 205C proved itself especially in civil aviation in long-range operations and was used in such legendary aircraft as the Junkers Ju 52, JU 86, as well as the Dornier Do 18, Do 24, Do 26 and the Blohm & Voss Ha 139.

After being recommissioned on 16.04.2015, the Jumo 205C has already been launched at the 10th Stationary Engine Meeting in Hundeluft (where it received a prize for the best original restoration) and at the Technology Museum in Magdeburg in front of many spectators fascinated by the old, yet innovative technology. And it certainly won’t be the last starts of the 77-year-old engine!