BMW 500 compressor
| BMW | |
|---|---|
 BMW 500 Compressor (1939) |
|
| 500 compressor | |
| Manufacturer | BMW |
| Production period | 1935 to 1939 |
| class | motorcycle |
| design type | Racing motorcycle |
| Racing series | 500 cc class |
| Motor data | |
| Two - cylinder boxer engine with vertical shafts and supercharger | |
| Displacement (cm³) | 493 cc |
| Power (kW / PS ) | 108 PS / 79.4 kW at 8000 min -1 |
| Top speed ( km / h) | 279.5 |
| transmission | 4-speed |
| drive | Cardan |
| Empty weight (kg) | 117 |
| Previous model | BMW WR 750 |
| successor | BMW RS 54 |
The BMW 500 compressor (also BMW RS 255 compressor ) was a racing motorcycle from BMW with two-cylinder - four stroke - boxer engine , which was used from 1935 to 1951 for races and record attempts.
history
Even the BMW WR 750 of 1929 received a forced induction by Zoller - compressor . The engine of the WR 750 came directly from the series models R 47 and R 57 . The WR 750 was mainly used for record drives by Ernst Jakob Henne , which was measured for the first time on September 19, 1929 at 216.75 km / h over the flying mile. The last record with the undisguised WR 750 was set on September 27, 1935: Henne drove 256.046 km / h over the flying kilometer on the newly opened Autobahn 5 between Frankfurt am Main and Darmstadt . However, design engineer Rudolf Schleicher recognized the performance limit of the bumper-controlled engine early on and developed an OHC valve control for the boxer engine in the early 1930s .
technology
The Rudolf Schleicher constructed Boxer motor, which line shaft driven overhead cam possessed and with a - mounted on the front side - Zoller-compressor was charged, reached 1935 on first attempt a power of 90 PS . The bore of the 493 cm³ engine is specified as 66 mm, the stroke as 72 mm. The engine output speed record machine (weight without covering: 117 kg) to 1937 between 105 PS and 108 hp at 8000 min -1 amounted, while the road racing machine (empty Weight 138 kg), depending on the source of "about" 50 horsepower at 6500 min -1 or 60 horsepower at 7000 min -1 is given. The performance was varied via the boost pressure (0.4 to 2 bar) and special fuel. Both versions had a four-speed gearbox, a curved tubular frame , which was later introduced in the BMW R 5 , telescopic fork , straight suspension and a tire size of 21 × 3 inches at the front and 19 × 3½ inches at the rear.
Record runs
On October 12, 1936, Ernst Jakob Henne set the first world record on Autobahn 5 with the fully faired BMW 500 Kompressor by completing the flying kilometer on the cordoned off autobahn near Frankfurt am Main at 272.006 km / h. The record run was not without problems; From 250 km / h onwards, the fully faired BMW showed strong chassis unrest. On the obligatory return trip, Henne was prepared for the lurching and was able to keep the movements of the motorcycle better under control. "Later, aerodynamicists determine that the motorcycle would inevitably have turned sideways at 280 km / h."
In 1937, an international competition for the absolute world speed record for motorcycles developed , in which three drivers took part: On April 19, 1937, Eric Fernihough beat the record on a Brough Superior with a 996 cm³ JAP engine and drove the kilometer in Hungary ( Gyón ) at 273.244 km / h. On October 21, 1937, Piero Taruffi increased the record with the Gilera Rondine to 274.181 km / h on the Autostrada near Brescia . Henne wanted the record back. In driving tests at the end of October 1937, however, it turned out that the previously used full fairing ("chicken and egg") on the BMW was not suitable for another record. During the subsequent revision of the full fairing, the side fins were removed, the tail fin lengthened and the viewing platform omitted; Henne drove again with his well-known teardrop helmet. On November 28, 1937, he set the world record for motorcycles on Autobahn 5 to 279.503 km / h (173.67 mph ), a record that lasted for 14 years and only on April 12, 1951 by Wilhelm Herz on NSU with 290.322 km / h h was outbid.
“Ernst Henne's motorcycle from the 30s [...] had hardly any suspension and was not stable at all. To drive at 280 km / h, to venture into unknown terrain, was a great challenge - mentally and physically. If we can drive 280 km / h with some series motorcycles today without any problems, we should not forget that this was only possible around '60 after Henne '. This underlines the pioneering achievement [...] "
A German special postage stamp from 1983 based on a design by Heinz Schillinger depicts the world record machine from 1937.
Road racing
From 1936 the BMW 500 Kompressor was used in all major European road races. In 1937 Karl Gall became German champion in the class up to 500 cc. The racing driver Georg Meier achieved his greatest success when he became European champion in 1938 and won the Isle of Man TT in 1939 on the BMW 500 Kompressor . After the Second World War , Meier, Ludwig Kraus and Walter Zeller drove the BMW 500 compressors in national championships until 1950, when the FIM compressor ban also applied in Germany.
The BMW RS 54 developed in 1953 is derived directly from the BMW 500 Kompressor. In 2013, a BMW 500 compressor was auctioned at Bonhams for 374,000 euros.
literature
- Fred Jakobs: Pre-war compressor has returned . In: BMW Group Mobile Tradition (Ed.): Mobile Tradition live . No. 03.2003 . Munich October 2003, p. 14-15 ( document in the BMW Group Archive [accessed November 12, 2014]).
Web links
- BMW Type 255. In: BMW History. BMW AG, accessed on October 21, 2014 (search in the BMW Group Archives).
photos
Video
Individual evidence
- ↑ a b c d e 100 years of Ernst Jakob Henne. (PDF; 2.9 MB) BMW Veteranen-Club Österreich, 2003, p. 29 ff. , Accessed on October 20, 2014 .
- ^ Christian Rey and Harry Louis: Famous Motorcycles . Wilhelm Heyne Verlag Munich, 1977, ISBN 3-453-52062-9 , p. 100
- ^ The Art Of The Motorcycle . Guggenheim Museum , Las Vegas, 2001, ISBN 0-89207-207-5 , p. 188
- ^ Siegfried Rauch: Famous racing motorcycles. 2nd Edition. Motorbuch Verlag, Stuttgart 1980, ISBN 3-87943-590-1 , p. 32
- ↑ Fred Jakobs: Pre-war compressor returned home . In: BMW Group Mobile Tradition (Ed.): Mobile Tradition live . No. 03.2003 . Munich October 2003, p. 14-15 ( document in the BMW Group Archive [accessed November 12, 2014]).
- ↑ a b c L. JK Setright: The Guinness Book of Motorcycling. Facts and Feats. 1982, ISBN 0-85112-255-8 , p. 238.
- ↑ The text: BMW world record machine 1936 is wrong. See 100 years of Ernst Jakob Henne. P. 41
- ↑ bonhams.com Auction 20469 (accessed October 20, 2014)
| class | Type | 1920s | 1930s | 1940s | ||||||||||||||||||||
| 3 | 4th | 5 | 6th | 7th | 8th | 9 | 0 | 1 | 2 | 3 | 4th | 5 | 6th | 7th | 8th | 9 | 0 | 1 | 2 | 3 | 4th | 5 | ||
| up to 250 cm³ | Touring motorcycle | R 2 | R 20 | |||||||||||||||||||||
| R 23 | ||||||||||||||||||||||||
| Sport motorcycle | R 39 | |||||||||||||||||||||||
| up to 500 cm³ | Touring motorcycle | R 32 | R 42 | R 52 | R 4 | |||||||||||||||||||
| R 3 | R 35 | |||||||||||||||||||||||
| Sport motorcycle | R 37 | R 47 | R 57 | R 5 | R 51 | |||||||||||||||||||
| up to 750 cm³ | Touring motorcycle | R 62 | R 11 | R 12 | R 71 | |||||||||||||||||||
| R 6 | R 61 | |||||||||||||||||||||||
| Sport motorcycle | R 63 | R 16 | R 17 | R 66 | ||||||||||||||||||||
| Prototypes, racing bikes | R 7 | |||||||||||||||||||||||
| WR 750 | R 51 RS | |||||||||||||||||||||||
| Military motorcycles | R 12 | |||||||||||||||||||||||
| R 75 team | ||||||||||||||||||||||||
