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1951 Norton International

1951 Norton International

The International was sort of the road-going version of Norton’s factory racer, the Manx. It came in two sizes: the 490 cc (500) Model 30 and the 349cc (350) Model 40. Both came with the Manx’s exotic shaft-and-bevel-gear-driven single overhead cam in a heavily-finned all-alloy top end. Because of their overhead cam configuration, which was quite rare and distinctive in the early 1950s. Because of this, the bikes, and the engines gained the nickname “Cammy Norton”. They were custom-built in the Norton factory to buyers’ specifications with different internal racing components. Privateers and factory teams alike rode Norton Internationals to numerous victories in the 1950s.

1951 Norton International SPECIFICATIONS

Engine type:


Bore & Stroke:

Compression ratio:

Fuel system:

Ignition system:

Charging system:

Engine output:

Top speed:

Primary drive:



Final drive:

Suspension, front:

Suspension, rear:

Brake, front:

Brake, rear:

Tire size, front:

Tire size, rear:


Dry weight:

Air-cooled SOHC single

490 cc / 29.9 ci

79mm X 100mm / 3.1″ X 3.9″


1X Amal carburetor

Lucas magneto

Lucan dynamo, 6-volt battery

29.5 horsepower @ 5500 rpm

93.2 mph / 150 kmh


Multi-plate, wet

4-speed constant mesh, right-foot shift


“Roadholder” telescopic forks

“Garden Gate” plunger-style

SLS drum

SLS drum

3.00″ X 21″

3.50″ X 20″

54.8″ / 1391 mm

388 lbs / 176 kg