1957 BMW 503 Cabriolet #157
Reconstruction
These were the use for the first time of a combined gearbox and differential unit in a transaxle assembly, and the provision of independent rear suspension. The company already had plenty of experience of both systems in their competition cars, the technology of which filtered through to the road models, another case of racing improving the breed.
The engine was an increased capacity derivation of the single overhead camshaft per bank V12 Colombo designed “short” block unit, with factory type reference 213, of 3286cc capacity, with a bore and stroke of 77mm x 58.8mm. It was fitted with a bank of either three twin choke Weber 40 DCZ/6 or 40 DFI/1 carburettors, or the optional six Weber 40 DCN3 assembly, with a twin coil and rear of engine mounted distributors ignition system, to produce a claimed 280bhp.
The engine drove through a shaft running at engine speed to a five speed transaxle which was independently supported from the chassis frame, and then by drive shafts to the independently suspended rear wheels, with wishbones, coil spring and hydraulic shock absorbers to each wheel. Initially the engine had four mounting points and the transaxle three, with sliding joints on the drive shaft between them. However, this proved difficult to maintain in alignment, and after trials, the final derivation was to adopt twin engine and transaxle mounting points with the drive shaft running within a solid tube connecting the two, making the engine and transaxle a rigid unit.
- Product Code: BMW 503 Cabriolet #157
- Availability: In Stock
- $0.00
BMW 503 Cabriolet
The BMW 503 is a two door 2+2 grand touring automobile from the 1950s. BMW developed the 503 alongside their 507 roadster in an attempt to sell a significant number of luxury cars in the United States. Hanns Grewenig, sales manager of BMW, repeatedly requested the development of a sports car based on their 501 and 502 luxury sedans. In early 1954, influenced by the public reaction to Mercedes-Benz 300SL and 190SL show cars in New York in February 1954, the management of BMW approved the project.
Max Hoffman, an influential automobile importer in the United States, saw early design sketches by BMW's Ernst Loof, and suggested to industrial designer Albrecht von Goertz that he should submit design proposals to BMW. Based on these proposals, BMW contracted Goertz to design the 503 and 507 in November 1954. The 503 was a 2+2 grand tourer that was available as either a coupe or a convertible. It was noted for having a cleaner and more modern design than the "Baroque Angel" 501-based sedans. The convertible version of the 503 was the first European convertible with an electrically operated top.
