EXCELSIOR

500 JAP Type B14 - 1932

Speedway power

In 1930, J.A. Prestwich, manufacturer of the universally-popular JAP engines, developed a special model destined for the new sport of speedway racing. These races, held on quartermile oval cinder tracks, had begun in the US and Australia before reaching Britain in 1928. They were an immediate success, and, in 1929, speedway races organized each week all over the country attracted up to 80,000 spectators.

Replacing the Rudge

In the beginning, the Douglas 500cc flat-twin was the ruling power unit, but in 1930, it was dethroned by the four-valve Rudge single. Realizing the prestige and importance of this growing market, JAP developed a competitive engine, which by late 1930 had taken a piece of the Rudge and proved itself the best-performing speedway engine.

Racing Possibilities

The racing world quickly recognized the possibilities of this new engine. In 1931, Fergus Anderson (who became World Champion on a works Moto Guzzi after WWII and was killed in 1956 on a works BMW 500) lapped Brooklands at 102.9 mph on an Excelsior equipped with a tuned JAP speedway engine. This model became famous under the name of B14. In 1932, it was marketed with a new 500cc racing JAP single. Based on the speedway unit, it had dry-sump lubrication (instead of total-loss) with an external Pilgrim pump that transferred the oil from the crankcase to a conventional tank. Charlie Dodson rode a B14 to fifth place in d1e 1932 Isle of Man Senior TT, at an average speed of 77.3 mph.

SPECIFICATIONS

Engine: 498cc (80x99mm) air-cooled single-cylinder four-stroke

Power Rating: 30 hp @ 5800 rpm

Valves: two-stroke twin side overhead camshafts

Fuel System: Amal carburetor

Transmission: 4-speed, chain primary and final drive

Suspension: Webb girder forks (front); rigid (rear)

Brakes: drum (front & rear)

Wheels: 19 inch (front & rear)

Weight: 280 lb

Maximum Speed: 100 mph

The 1932 Excelsior B14 was equipped with a tuned 500cc JAP speedway engine that was as light as it was powerful.