NSU Dolphin III

NSU Delphin III replica

The NSU Delphin III was a record-breaking vehicle from NSU Motorenwerke , with which racing driver Wilhelm Herz in the USA reached an average speed of 339.404 km / h on the Bonneville Salt Flats on August 4, 1956 , thus improving the absolute motorcycle speed record.

Beginnings

Walter William Moore, of the motor of the later famous Norton constructed, had 1929 as the new chief designer, the vertical shaft also introduced at NSU, most recently the two V-like arrangements on the compressor - two-cylinder , which he, together with Albert Roder 1938 developed. Wilhelm Herz used the relatively heavy unit in its 350 cm³ version in races in 1939 . Herz was also among the first to find out in Neckarsulm after the Second World War whether a compressor machine could still be found. A slightly damaged copy was found, it repaired the old British compressor and in 1948 became German champion in the 350 cc class . At the same time, the long-cherished plan to tackle the absolute speed record for motorcycles took shape: According to designs by aerodynamicist Reinhard von Koenig-Fachsenfeld , a machine was created at Herz's expense that resembled Ernst Jakob Henne's record-breaking BMW .

The "world record" as a project of the NSU factory

Having reached the test stage in 1949, the "Fachsenfeld" was not used after all. Herz was seriously injured in a fall and while he was convalescing , NSU developed the Delphin I under the racing department manager Walter Froede with the help of the Braunschweig Technical University . The driver's head, shoulders and back barely protruded from the 50 kg streamlined fairing ; the 500 cc engine, equipped with a newly developed compressor, developed 110 hp at 8500 rpm and Herz reached an average speed of 290 km / h on the Munich-Ingolstadt motorway on April 12, 1951 - Hennes's 1937 record was broken.

Where everyone drives - on American salt

The value was improved in New Zealand , where on July 2, 1955, Russel Wright on a Vincent set himself the record holder with 297.64 km / h. Competitors also appeared in the USA, the team of Texan J. H. "Stormy" Mangham achieved an average of 311.19 km / h with the Devil's Arrow on September 22, 1955 on the salt lake near Wendover . Driver Johnny Allen was now the record holder on the AMA list , but not on the FIM , which wanted its own timekeeper on site. In the late summer of 1956, a direct comparison was made between the Texans and an NSU works team who had traveled with all aids on the Bonneville Salt Flats. A mobile workshop was brought up by ship, equipped with spare parts for the machines in the six motorcycle classes from 50 to 500 cm³ displacement . General director Gerd Stieler von Heydekampf was present, as was his deputy and technical director Viktor Frankenberger.

The conditions were changeable for Herz during the first record attempts with the newly built Delphin III : A wet spot in the salt made him stray from the track and he touched the container of a light barrier , which tore a hole in the nose of the cladding. The surface of the runway was so rough that using the cabin cover was out of the question - the space for the driver's head was too tight given the vibrations that occurred. This not only robbed the development progress of the Delphin III - the shape had been optimized in a Stuttgart wind tunnel - driving without a hood made the machine unstable, lead ballast had to be attached near the front fork . With a hole cut in the hood, the motorcycle resembled the Dolphin I again . But even without a top, Herz achieved a value of 304.96 km / h on August 2, 1956 with the 75 hp 350 cm³ engine for the flying mile and on August 4 with the 500, an average of 339.404 km / h - newer absolute world record for motorcycles.

Russel Wright was there, but drove his 1000 cc Vincent no faster than 319 km / h. A good month later, the Texans got back on track and raised the record to 345 km / h with their 650 triumph “Streamliner” (without compressor). As usual, an FIM timekeeper was saved and there was no official international recognition. The American William A. Johnson only got it in 1962 when he set a world record of 361 km / h with the Dudek Triumph Streamliner .

Technical specifications

General data

Wheelbase:	1600 mm
Dimensions L × W × H:	3700 × 640 × 1100 mm
Vehicle weight:	265 kg
Top speed:	approx. 340 km / h

engine

NSU:	from the half-liter compressor racing machine
Working method:	Four-stroke Otto
Cylinder:	2 / row, wind-cooled
Displacement:	498 cc
Bore × stroke:	63 × 80 mm
Power:	110 hp at 8500 rpm
Compression ratio:	7.0: 1
Valves:	V-shaped hanging, 2 overhead camshafts
Mixture preparation:	1 Amal TT 28 racing carburetor
Fuel delivery:	Gravity, tank above the engine
Ignition:	Bosch - magneto ignition

Power transmission

Drive:	Chain drive on the rear wheel
Coupling:	Multi-disc clutch
Transmission:	4-speed manual transmission
Circuit:	Foot switch

landing gear

Frame:	Double tubular steel frame with light metal cladding
Suspension:	front trapezoidal fork with coil spring and hydraulic shock absorber, rear telescopic suspension and hydraulic shock absorber
Brakes:	front and rear drum brakes
Steering:	Steering head with tubular handlebar
Bikes:	Wire spoke wheels
Tires:	front 3.25 × 18 inches, rear 3.50 × 20 inches

literature

Peter Schneider: The NSU-Story , Motorbuch Verlag, Stuttgart 2012, ISBN 978-3-613-03397-9 , pp. 92, 129-132, 176-178 u. 354
W. Froede: From the development of the NSU world record motorcycle , Automobiltechnische Zeitschrift (ATZ) 56 (1954), No. 5, pp. 127–130.

Web links

Commons : NSU Delphin III - collection of pictures, videos and audio files

Individual evidence

[1] Wilhelm Herz. Stations of a motorsport legend, website "wilhelmherz.de" (PDF file, 34.2kb, accessed on October 6, 2013)

[2] Mit der Nasenspitze , Der Spiegel 16/1951, pp. 15-16

[3] Mick Walker: Mick Walker's German Racing Motorcycles , Redline Books, Low Fell 1999, p. 202