Beschreibung:

An important step forward in the development of BMW's long-running flat-twin occurred in 1936 with the introduction of the 494cc R5. Prior to that the BMW engine had been recognizably related to the first of its type, the 1923 R32, and like those of its (500cc) predecessors, the R5's engine dimensions were 'square' at 68x68mm bore/stroke. However, the overhead-valve R5 engine broke new ground by adopting two chain-driven camshafts, a move that permitted shorter pushrods and higher revs. In 1938 the model was updated as the R51 and continued in production until 1940. BMW recommenced twin production in December 1949 with the R51/2 based, as its designation suggests, on the pre-war R51. In truth, the R51/2 was only a stopgap model to get production under way while BMW worked on something more modern. Its replacement, the R51/3 - arrived in February 1951, and despite the similarity in designation had an entirely new and much neater looking engine incorporating a single gear-driven camshaft and crankshaft-mounted generator among a host of other advances. There was also a 600cc R67 version, intended primarily for sidecar duty, which was swiftly superseded by the more powerful R67/2 for 1952. This is an authentic club racer built in Germany in the 1950s using a 500cc version of the R67/2 motor. It was raced for the best part of 20 years in Germany before being imported into the USA. It has then been raced some more, for another 20 years by our vendor. Many original German racing parts, now very rare, remain installed such as the Hoske magnesium wheel hub, Magura controls, Hoske fuel tank, and VDO tach. Its full race engine is still fueled by a pair of Dell'Orto "sidecar" carburetors. This outfit was last raced at the AHRMA event at Barber Motorsports Park in October of 2013. It is reportedly in race ready condition but the buyer would be wise to carefully inspect the machine. And it comes complete with an invitation to join the vendor's race team at the 2014 AHRMA/Barber fall meeting.