Guide: BMW 507
Background
BMW started life as a builder of aircraft engines in 1913.
After World War 1, the company remained in business by producing motorcycle engines, farm equipment, domestic items and railway brakes.
BMW produced its first complete motorcycle, the R 32, in 1923.
In 1928, the acquisition of Fahrzeugfabrik Eisenach, which built Austin Sevens under licence, meant BMW became an auto maker as well.
During World War 2, BMW concentrated on the production of aircraft engines. The firm primarily used forced labour from concentration camps.
Following the end of hostilities, the company was temporarily banned from making aircraft engines and automobiles.
BMW resumed manufacture of motor cars in 1952 when the straight six-powered 501 luxury saloon was launched.
In 1954, the company unveiled the 502 which was powered by an all-alloy overhead valve 2.6-litre V8 that had been in development since 1949.
Upon seeing the new V8-powered line, BMW’s American distributor, Max Hoffman, persuaded the firm to build a two-seat roadster. If the car could retail at $5000, Hoffman thought he could sell around 5000 every year.
Hoffman envisaged the BMW roadster to be a mid-range model, simpler and less expensive than the 300 SL Gullwing he had convinced Mercedes-Benz to produce.
The BMW 507 prototype was unveiled at New York’s Waldorf-Astoria Hotel in August 1955.
In September 1955, the 507 starred at the Frankfurt Motor Show where it was displayed alongside three other models that also used BMW’s newly reworked 3.2-litre V8. These were the 503 Coupe, the prototype 505 limousine and the BMW 3.2 saloon (a development of the 502).
507 production began in November 1956.
To save money, it was designed to incorporate as many existing components as possible.
Chassis
The 507’s tubular steel chassis was a shortened version of the 503 frame. The wheelbase was reduced from 2835mm to 2480mm. Track was widened by 45mm at the front and 25mm at the rear.
Suspension comprised double wishbones at the front and a live axle with Panhard rod at the back. Adjustable torsion bars were fitted all round along with a front anti-roll bar.
Hydraulic self-adjusting Alfin drum brakes had a 284.5mm diameter and were servo-assisted.
The steel 16-inch wheels measured 6-inches wide. They originally came with body coloured centres, a chrome hub cap and Pirelli Cinturato tyres.
An enormous 110-litre fuel tank was located behind the rear seats.
Engine & Gearbox
BMW’s all-alloy 90° V8 featured a coolant passage that increased block stiffness over typical engines with wet cylinder liners.
A central camshaft used pushrods to operate overhead valves in crossflow cylinder heads with wedge-shaped combustion chambers.
For BMW’s new range of models, engine displacement rose from 2.6 to 3.2 litres. This was achieved by increasing the bore from 74mm to 82mm. Stroke remained at 75mm for an overall displacement of 3168cc (a gain of 588cc).
The Type M507/1 engine fitted to the 507 (and the M503/1 used by the 503) featured a pair of Zenith 32 NDIX carburettors. The 507 unit also came with a 7.8:1 compression ratio (up from 7.5:1), high-lift camshafts, polished combustion chambers and a different spark advance curve.
Peak output was 150bhp at 5000rpm and 173lb-ft at 5000rpm.
Transmission was via a four-speed all-synchromech close-ratio manual gearbox and single plate Fichtel & Sachs clutch.
Bodywork
BMW’s first port of call to style the 507’s bodywork was Ernst Loof. However, Loof’s design was rejected by Hoffman who had already placed a large order and was therefore permitted considerable influence over the process.
Hoffman requested freelance designer Albrecht Goertz be given the commission.
Goertz, a US-domiciled German, had established his own design business in 1953 and, with the 507, he created arguably one of the best looking cars of its era.
The front end incorporated BMW’s trademark kidney grilles. Exposed headlights were mounted at the leading edge of curvaceous wings.
Down the flanks, delicate swage lines trailed out behind each wheelarch and engine cooling vents were given elaborate chrome inserts.
Rear fenders were subtly finned and full width chrome bumpers were fitted at either end.
The 507’s body was created almost entirely from hand-beaten aluminium which proved time consuming and expensive. It also meant panels differed from car to car and were not easily interchangeable.
Interior
Inside, leather was used to cover the dash top, seats, door panels and lockable rear bulkhead.
The Bakelite steering wheel had four arced spokes and an ivory or black finish to match the knobs on the dash, gear lever and seat adjusters.
Directly behind the steering wheel was an instrument binnacle that housed a speedometer, rev counter and clock. The dash fascia and instrument surround were usually painted body colour.
When lowered, the roof stowed underneath a canvas cover that lay flush with the rest of the rear deck.
Options
Optional extras included centre lock Rudge wheels, an aluminium hardtop, alternative axle ratios, chrome exhaust tips, a choice of radio equipment and a high-intensity horn.
There was also a tuned 165bhp engine which featured an even higher 9.0:1 compression ratio, a bigger ratio for the camshaft rocker arm and larger 42mm inlet and 38mm outlet valves.
Weight / Performance
BMW quoted a kerb weight of 1315kg, a top speed of 127mph and 0-62mph time of 11.1 seconds.
Production
Because of higher than anticipated production costs, the 507’s list price ultimately rose to nearly double the $5000 Max Hoffman had expected.
In the USA, the 507 cost only a fraction less than a Mercedes-Benz Gullwing while, in the UK, the BMW roadster was even more expensive than an Aston Martin.
After 34 cars had been built, BMW introduced a Series 2 derivative in early 1957.
Series 2
The Series 1’s 110-litre fuel tank located behind the seats allowed fumes into the cockpit and was also an inefficient use of space. Accordingly, the Series 2 came with a smaller 65-litre tank fitted in the boot floor around the spare wheel.
Cosmetically, the Series 2 featured a bigger dash with re-positioned switchgear, an integrated speaker and larger glovebox. The passenger grab handle was moved from the dash top to the dash fascia. As before, the ventilation controls were located in a panel under the centre of the dash.
Series 2 Production Changes
Late Series 2s came with Girling front disc brakes.
End of Production
Production of the 507 was discontinued in December 1959.
By this time, 252 had been completed (34 from Series 1 and 218 from Series 2).
Famous owners included John Surtees, Elvis Presley, Alain Delon, Ursula Andress, Prince Rainier of Monaco, Prince Sadruddin Aga Khan and the kings of Greece and Morocco.
Competition History
BMW prepared two 507s for mild competition use.
Chassis 70079 (the car later leased to Elvis Presley) was driven by Hans Stuck who had an ambassadorial role promoting the 507.
Stuck drove 70079 at three European Hillclimb Championship events in the summer of 1958. He most notably placed fifth in the GT class at Freiburg-Schauinsland and followed this up with appearances at Gaisberg and Ollon-Villars.
In 1959, Stuck drove another 507 (chassis 70145) at the Gaisberg, Klosters-Davos and Wurzenpass hillclimbs. His best result that season was fifth overall and second in the GT category at Gaisberg.
507 Michelotti-Vignale
At the Turin Motor Show in 1959, Giovanni Michelotti in conjunction with Vignale showcased a 507 Roadster with hard top designed to illustrate how a successor to the 507 might look.
Built on chassis 70184, the handsome machine remained a one off although Michelotti was subsequently rewarded with a contract to design the BMW 700.
Legacy
Although the 507 kept BMW in the limelight, a substantial sum was lost on every car sold.
Only an infusion of capital from German industrialist, Herbert Quandt, saved BMW from bankruptcy.
Quandt ultimately took a 50% stake in the company and played an instrumental role financing the 700 and 1500 models which reversed BMW’s fortunes.
Text copyright: Supercar Nostalgia
Photo copyright: BMW - https://www.bmw.com
