Photo ou archives : F-M. Dumas
351 SSR Twin-Cam Works Racer - 1937
Chasing after Norton
In 1930, in order to defeat Norton in international racing, NSU raced its Bull us overhead-cam single (designed by Walter Moore) but without success; the same went for the 350 version of 1934. A works variant with twin overhead-cams was produced in 1937 for the NSU team of Heiner Fleischmann, Karl Bodmer and Werner Mellman.
This 351 SSR raced in 1937 and 1938 but was supplanted by NSU's supercharged 350 twin. It reappeared from 1946 until1949, ridden in Germany and Austria by Karl Bodmer and Kurt Nitschky.
Just one 350 SSR survives, and it was restored by German NSU specialist Karl Reese. The twin ohc 351 SSR had the same bore and stroke as the preceding sohc model, which appeared in 1934 and was sold in tiny numbers from 1935 to 1938. The quoted power of 25 hp at 6800 rpm for the 1935 single-cam NSU rose with the 1937 twin-cam version. The 500 SSR, with dimensions of 80x99mm, gave 32 hp at 5800 rpm in its sohc version of 1935 and 36 hp at 6000 rpm with the dohc in 1937. The increase was insufficient to match the works Nortons Â– the NSUs were giving away 2 to 3 hp in 350cc form and 3 to 4 hp in the 500cc class. Moore, still technical director of NSU at the time, could not beat his adversary Joe Craig. Another reason NSU switched to a supercharged twin was DKW's 1938 withdrawal from the 500cc class to concentrate on the 350cc category with its pumping-piston racers.
Engine: 349cc (77x88mm) air-cooled single-cylinder four-stroke
Power Rating: 31 hp @ 7000 rpm
Valves: twin overhead-camshafts
Fuel System: 29.4mm TT carburetor, inclined at 15 degrees
Transmission: 4-speed racing gearbox, chain final drive
Suspension: Webb-type girder forks (front); rigid (rear)
Brakes: drum (front & rear)
Wheels: 3x21 inch (front); 3.25x19 inch (rear)
Weight: 287 lb (1935 SSR, 313 lb)
Maximum Speed: 103 mph
The only remaining example of the NSU 351 SSR Twin-Cam Works Racer is still a masterpiece of finish and technical sophistication.