The world’s only tried and tested aircraft diesel opposed-piston engine that is still capable of running was started up for the first time after a long period of restoration at the 9th Dessau Gas Engine Conference on 16.04.2015 in front of an excited public at the Hugo Junkers Technological Museum in Dessau.
The Jumo 205C aircraft engine, which was built in 1938 by Mitteldeutschen Motorenwerke GmbH and developed by Hugo Junkers, is on loan from the Technological Museum in Magdeburg.
Our Mr. Möller subjected the Jumo 205C to a comprehensive restoration that took almost two years at WTZ. At 80 years old, Mr. Möller is older than the engine itself. After the restoration of the engine, all of the circuits, tanks, a motor frame as well as a compressed air starting device that were needed for subsequent operation were assembled. The culmination of the assembly was the attachment of an original Junkers wooden propeller, which the Hugo Junkers Technological Museum in Dessau kindly made available to us. The Jumo 205C was therefore a true aircraft engine again.
The 6-cylinder series diesel opposed-piston engine with a maximum performance of 600 HP, has two crankshafts and operates as a two-stroke piston combustion engine, whereby two pistons work against one another in the same cylinder and share the same combustion chamber in the middle of the cylinder. Two diesel injection pumps and four diesel injectors are assigned to each combustion chamber.
This kind of engine is lightweight, compact, more efficient and consumes about 30% less fuel than conventional aircraft engines. The Jumo 205C particularly proved itself on long haul flights in civil aviation, and was used in such legendary aircraft as the Junkers Ju 52, the JU 86 and Dornier aircraft Do 18, Do 24, Do 26 and the Blohm & Voss Ha 139.
After the recommissioning on 16.04.2015, the Jumo 205C has been started at the 10th stationary engine meeting (Stationärmotorentreffen) in Hundeluft (where it won an award for the best original restoration) and at the Technological Museum in Magdeburg in front of the many spectators who were fascinated by the old but innovative technology. And it is certainly not the last time that the 77 year old engine will be started!