BMW 303
BMW | |
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BMW 303 Cabriolet (1934)
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303 | |
Production period: | 1933-1934 |
Class : | Lower middle class |
Body versions : | Limousine , cabriolet |
Engines: |
Petrol engine : BMW M78 (1182 cm 3 , 22 kW) |
Length: | 3900 mm |
Width: | 1440 mm |
Height: | 1550 mm |
Wheelbase : | 2400 mm |
Empty weight : | 820 kg |
successor | BMW 315 |
The BMW 303 was a car that BMW built in its Eisenach plant in 1933/1934. It was the first BMW vehicle with a six-cylinder engine and the kidney-shaped radiator grille that still characterizes the brand's cars to this day.
history
development
In 1931, based on a cooperation agreement with Daimler-Benz , BMW decided to develop a new car with a displacement of up to 1.3 liters and a six-cylinder engine above the successful BMW 3/20 .
engine
At the main plant in Munich , Max Friz designed an engine with overhead valves ( OHV ), an engine block and cylinder head made of an aluminum alloy , which was very advanced for the time ; In Eisenach, however, his former colleague Martin Duckstein designed a conventional design with vertical valves ( SV valve control ) and only three crankshaft bearings . The crankcase and cylinder head were made of gray cast iron .
In the summer of 1932, General Director Popp commissioned the test manager Rudolf Schleicher to assess the competing engine concepts. Then Schleicher and his colleague Karl Rech presented their own design: engine block and cylinder head made of inexpensive gray cast iron, but with four instead of three crankshaft bearings and OHV valve control. It was supplied with a fuel-air mixture by two ascending flow carburetors . Schleicher and Rech introduced the proven and successful modular concept of BMW motorcycles into car construction at BMW. Many parts were the same as in the four-cylinder engine of the BMW 3/20 and therefore the six-cylinder could also be machined on its production machines. American design principles of large-scale construction served as a role model - after all, produced BMW since 1928 the nine-cylinder - aircraft engine BMW Hornet , a manufacture under license of the Pratt & Whitney R-1690 .
Hans Nibel , chief developer at Daimler-Benz and a good friend of Franz Josef Popp, was finally consulted and immediately decided on the design by Schleicher and Rech, which was then implemented.
chassis
The chief designer Fritz Fiedler , who had only switched from Horch in Zwickau to BMW in August 1932 , found a new ladder frame made of open ( U-shaped ) profiles for the 303 in Eisenach , but this did not meet his requirements. In a short time he designed a lighter construction with round longitudinal tubes and box-shaped crossbars . This also made the basis of the chassis trend- setting for the following years.
marketing
BMW presented the Type 303 in February 1933 in Berlin at the 24th International Automobile and Motorcycle Exhibition (IAMA).
A choice of three bodies was offered: a 2-door sedan with 4 seats (RM 3600, -), a 2-door convertible with 4 seats (RM 4400, -) and a 2-door sports convertible with 2 seats (RM 4600 , -).
After 2,300 vehicles had been built, the BMW 315 with a more powerful engine came onto the market in 1934 as a successor.
technology
engine and gears
Were driven vehicles from a six-cylinder in-line engine (constructed by Rudolf Schleicher) with 1173 cc displacement, the at 4000 min -1 issued a power of 30 HP (22 kW). The engine power was transmitted to the rear wheels via a four-speed gearbox with center shift. The top speed was 90 km / h.
Body and chassis
The front wheels were suspended individually : the double wishbone axle consisted of an upper transverse leaf spring and triangular links below, the rigid rear axle was guided on semi-elliptical longitudinal leaf springs. All wheels had mechanically ( cable ) operated drum brakes .
literature
- Werner Oswald : All BMW automobiles 1928–1978 . Motorbuch Verlag, Stuttgart 1980, ISBN 3-87943-584-7 .
Web links
- Manual for the 1.2 Ltr / 30 HP 6 cylinder BMW. In: BMW history. BMW AG, July 1933, accessed on January 16, 2016 (manual with pictures, 95 pages).
- Spare parts list and tables for the 1.2 liter / 30 PS BMW 6 cylinder car. In: BMW history. BMW AG, November 1933, accessed on January 16, 2016 (complete spare parts list with pictures, 110 pages).
- Proper lubrication of the 1.2 liter BMW car. In: BMW history. BMW AG, 1933, accessed on January 16, 2016 (lubrication plan with pictures).
Individual evidence
- ↑ a b c d e f g Walter Drawer: Mobile Tradition live: The beginning of a long tradition. 70 years ago - BMW 303, the first six-cylinder car. In: BMW history. BMW AG, July 2003, pp. 8–11 , accessed on January 14, 2016 (Mobile Tradition live - Edition 02 / July 2003).
- ↑ Model BMW 303. In: BMW History. BMW AG, accessed on January 16, 2016 (dossier in the BMW Group archive with technical data).
- ↑ BMW M78 automobile engine 1.2 liters. In: BMW history. BMW AG, accessed on January 16, 2016 (dossier in the BMW Group archive with technical data).
- ↑ BMW 303 front axle and engine (chassis). In: BMW history. BMW AG, 1933, accessed on January 16, 2016 (photo in the BMW Group Archive).
Timeline of the Dixi , BMW and EMW models from 1927 to 1955 | |||||||||||||||||||||||||||||||
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Type | 1920s | 1930s | 1940s | 1950s | |||||||||||||||||||||||||||
6th | 7th | 8th | 9 | 0 | 1 | 2 | 3 | 4th | 5 | 6th | 7th | 8th | 9 | 0 | 1 | 2 | 3 | 4th | 5 | 6th | 7th | 8th | 9 | 0 | 1 | 2 | 3 | 4th | 5 | 6th | |
Small car | Dixi 3/15 | ||||||||||||||||||||||||||||||
BMW 3/15 | 3/20 | ||||||||||||||||||||||||||||||
Lower middle class | 309 | ||||||||||||||||||||||||||||||
303 | 315 | ||||||||||||||||||||||||||||||
Middle class | 319/329 | 320 | 321 | ... | 321/2 | ||||||||||||||||||||||||||
326 | ... | 326/2 | 340 | EMW 340 | |||||||||||||||||||||||||||
upper middle class | 335 | ||||||||||||||||||||||||||||||
Roadster / Coupé / Convertible | BMW Wartburg | 315/1 / 319/1 | 327 | ... | 327 | EMW 327 | |||||||||||||||||||||||||
328 | |||||||||||||||||||||||||||||||
Kübelwagen | 325 | EMW 325 | |||||||||||||||||||||||||||||
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