Mercedes-Benz OM 85

The Mercedes-Benz OM 85 was a high-speed twelve-cylinder four-stroke diesel engine built for the fast railcars of the Deutsche Reichsbahn. It was first used in 1934 and was renamed MB 805 in 1938. Nine examples were installed in railcars of the pre-war type, and it can be seen as a development of the many six-cylinder four-stroke diesels of the two-axle railcars, with a smaller bore and shorter stroke than the six-cylinder engines of the same output. The twelve cylinders stood in a 60 degree V, the engine was naturally aspirated with pre-chamber injection, and it was carried together with its main generator in a subframe in the bogie. A version with higher output followed from 1937 as the Mercedes-Benz OM 86. Before the Second World War the railcars fitted with it averaged about 76,000 km a year.