BMW 501


The BMW 501 was a luxury car manufactured by BMW from 1952 to 1958. Introduced at the first Frankfurt Motor Show in 1951, the 501 was the first BMW model to be manufactured and sold after the Second World War, and the first BMW automobile actually built in Bavaria. The 501 and its derivatives, including the V8 powered BMW 502, were nicknamed “Baroque Angels” for their graceful if dated styling by the German public. The BMW 502 was the first postwar German car to be manufactured with a V8 engine.
While the 501 and 502 model numbers were discontinued in 1958, variations of the model, with the same platform and body, were continued until 1963.

Background

Awtowelo restarts "BMW" production

BMW's World War II-era satellite motor car factory in Eisenach fell in the post-war Soviet occupation zone in the newly created Communist GDR. Manufacturing of pre-war BMW models was restarted postwar in late 1945 by the Soviet created entity Sowjetische AG Maschinenbau Awtowelo. Despite not being made by BMW AG, these cars bore the BMW logo and were being sold as BMWs.
Meanwhile, BMW AG in Bavaria restarted manufacture on a much smaller scale, beginning with pots and pans and eventually moving up to household hardware and bicycles. Eventually, with permission from the U.S. authorities and funding from the banks under which BMW had been put into receivership, it began manufacturing motorcycles in 1948.
To end Awtowelo's continued trademark infringement, the Eisenach branch of BMW was legally dissolved effective 28 September 1949 and severed as of 11 October. To avoid illegally using BMW's name and logo, Awtowelo simply renamed the concern EMW in 1952, retained all the tooling and equipment, and replaced the blue in the BMW logo to red.

Three approaches to car manufacture

Donath

Kurt Donath, technical director of BMW and general manager of the Milbertshofen factory, was soliciting manufacturers, including Ford and Simca, to produce their vehicles under licence. In particular, Donath was looking to produce old products under licence, so that he could buy tooling along with the licence.

Böning

While Donath was trying to find a car to build under licence, chief engineer Alfred Böning developed a prototype for a small economy car powered by a motorcycle engine. Called the BMW 331, the prototype used a 600 cc motorcycle engine, a four-speed gearbox, and a live rear axle. The body was designed by Peter Szymanowski and resembled a BMW 327 in miniature.

Grewenig

The BMW 331 was proposed for production to the management, where it was vetoed by sales director Hanns Grewenig. Grewenig, a banker and former Opel plant manager, believed that BMW's small production capacity was best suited to luxury cars with high profit margins, similar to the cars BMW made just before the war. To this end, he had Böning and his team create the car that would become the 501.

Design and engineering

The 501 was an all-new platform, with a perimeter frame, double A-arm front suspension with torsion bar springs, and a live axle with torsion bar springs at the rear. The steering mechanism was similar to a rack and pinion system except that the rack was semi-circular instead of straight.
The 501 was powered by the 2 L straight-6 OHV M337 engine, a development of the BMW M78 used in the pre-war BMW 326.
The four-speed gearbox was not bolted to the engine, but was a separate shaft-driven unit mounted between the second and third crossmembers. While the remote gearbox placement led to a complicated linkage to the column-mounted shifter, resulting in vague shifter action, it also improved legroom for the front passengers.
The body was designed in house by Peter Szymanowski. After seeing the prototype, BMW's management commissioned Pininfarina to build an alternative. The Pininfarina prototype was thought to be too similar to his design for the Alfa Romeo 1900 saloon, so BMW stayed with Szymanowski's design. The steel body was far heavier than Szymanowski had calculated it to be, resulting in the completed car having a dry weight of. Performance suffered as a result, with a top speed of and acceleration to taking 27 seconds, both of which compared unfavourably with the six-cylinder Mercedes-Benz 220.
One innovation was the attention paid to passive safety. The car featured a robust chassis providing above average side impact protection, an unusually short steering column with the steering gear set well back from the front of the car, and a fuel tank placed in a carefully protected location above the rear axle in order to minimize fire risk in the event of an accident.

Reception and production

The 501 was introduced to the public in April 1951 at the Frankfurt Motor Show, as was its less expensive, production-ready rival, the Mercedes-Benz 220. The 501 made an impression on the public with its solid engineering and its extravagance. Its list price of more than fifteen thousand Deutsche Mark was about four times the average yearly salary in Germany at the time. The public nicknamed the 501 "Barockengel" in reference to the curved, flowing style of the body, which was reminiscent of the Baroque era.
Development issues delayed the start of production until late 1952, and even then BMW still did not have equipment for pressing body panels in operation. The first 2,045 four-door saloon bodies were built by Karosserie Baur and were shipped from Baur in Stuttgart to BMW's factory in Munich for assembly. The thousandth 501 was completed on 1 September 1953.
The 501 and derivatives built at BMW were four-door saloons. Coupe and convertible versions were available as custom orders from Baur or Autenrieth.
A road test of the 501 in March 1953 by Auto- und Motorrad-Welt reported better than average wind resistance, as well as good ride quality and an effective heating system. The fuel consumption was reported to be.

Development of the BMW 501

The 501A was released in 1954 as a replacement for the original 501 with similar trim and equipment, but which sold for DM14,180, a price reduction of more than eight hundred Deutsche Mark from the original 501. The 501B was a decontented version that sold for DM500 less than the 501A. Both the 501A and 501B used a revised M337 engine.
The engine and the model designation were altered again in the spring of 1955. The 501A and 501 B were replaced by the 501/3, with an updated M337 engine. The 501/3 was introduced alongside the 501 V8, which featured a detuned version of the 2.6-litre V8 introduced in the 502 the previous year. The 501/3 and 501 V8 were continued until 1958, when the six-cylinder engine and the 501 model designation were discontinued.

BMW 502

Before the construction of the first prototype of the 501, Böning had calculated the mass of the car as designed, and realized that the six-cylinder engine would be barely adequate to power the car. He proposed the development of a larger engine to power future versions to the management, who accepted his proposal. Böning began the design and development of a V8 engine similar in general design to the then-new overhead valve Oldsmobile Rocket V8, with a single in-block camshaft operating overhead valves in wedge-shaped combustion chambers through pushrods. The BMW OHV V8 engine differed from its Detroit contemporaries in the use of an aluminium alloy block with cast-iron cylinder liners, and in being half the size or smaller, initially with a bore and a stroke, giving a displacement of. The development of the V8 was completed by Fritz Fiedler, who replaced Böning as BMW's chief engineer in 1952.
The V8 engine was introduced at the 1954 Geneva Motor Show as the engine of the new BMW 502 saloon car. Using the same chassis and basically the same body as the 501, the 502 was more luxuriously appointed and, with its light V8 engine producing with a single two-barrel Solex carburettor, was much faster. The published top speed of was far higher than that of the first six-cylinder version of the Ponton Mercedes launched the same year. At the time of its introduction the 502 was reportedly Germany's fastest production passenger sedan.
The 502 was acclaimed as Germany's first post-war V8 powered car, but its high price of DM17,800 led to low sales; only 190 were sold in its first year of production.
The 502 was distinguished from the 501 by additional chrome trim and more lavish interior fittings. Fog lights and individual front seats were also now included as standard features. The 502 was mildly restyled in 1955 with a wraparound rear window.
As well as the saloon version, BMW offered Baur built two-door cabriolet and coupé versions of the 502 in 1954 and 1955. 501s and 502s were also converted into ambulances and hearses.

BMW 2.6 and 2.6 Luxus

The 501 and 502 model designations were discontinued in 1958, when the 501 V8 was renamed the BMW 2.6 and the 502 was renamed the 2.6 Luxus. The cars were continued under these model designations until 1961 with only two notable changes: power steering became an option in 1959, while front disc brakes were added in 1960.

BMW 2600 and 2600L

In 1961, the model designations were changed again, to 2600 and 2600L. The engine in the 2600L was tuned to give. Production ended in 1963.

BMW 3.2 and 3.2 Super

A further development of the V8 engine was introduced at the 1955 Frankfurt Motor Show. The engine had a bore, giving a capacity of . The engine made its debut in four new cars at the show, the 507 two-seat gran turismo, the 503 2+2 gran turismo, the 505 limousine prototype, and the BMW 3.2, a development of the 502 that did not have a model number and was identified simply by its displacement in litres. As used in the 3.2 and the 505, the engine had a compression ratio of 7.2:1, up from the 7.0:1 of the original 2.6 L V8 engine. In this tune, the engine yielded The final drive ratio was raised from 4.225:1 on the smaller-engined sedans to 3.89:1 on the 3.2 to reduce the fuel consumption of the larger engine.
In 1957, the 3.2 Super with a engine, was released. The 3.2 and 3.2 Super were continued under these model designations until 1961 with only two notable changes: power steering became an option in 1959, while front disc brakes were added to the 3.2 Super in October 1959 and to the 3.2 in 1960.