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Vintage Motorcycles: J.A. Prestwich JAP Engines

Vintage J.A. Prestwich Engine

J.A. Prestwich Industries Ltd. History

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The firm of JA Prestwich Industries Ltd. in Middlesex was one of Britain's premier motorcycle engine manufacturers, founded by John Alfred Prestwich (1874—1952) in 1895. The mechanically inclined engineer also collaborated with inventors Sebastian S.Z. de Ferranti and William Friese-Greene to produce cinematographic projector equipment, which the company was as famous for as their legendary, and colloquially-known 'JAP' motorcycle engines.

Throughout the early 1900s, the Prestwich factory on Tariff Road in Northumberland Park, Tottenham, Middlesex, built engines for some of Britain's most famous motorcycle marques. These included Ariel, Brough, HRD (Vincent), Matchless, New Imperial, Royal Enfield, Triumph and Rudge to name only a few.

JA Prestwich Engine in Morgan 3-Wheeler
JA Prestwich Engine in the Morgan 3-Wheeler

The company also exported engines to foreign motorcycle companies such as Dresch of âtampes, France; Terrot of Dijon, France; Ardie in Nčrnberg, Germany; and Tornax in Wuppertal, Germany.

The JAP 'Vee Twin' Engine

The J.A.P. 'Vee Twin' was Britain's answer to the large-displacement Indian v-twins that America was producing at the time. John Prestwich was able to procure Bert Le Vack, a British national who was working for Indian, to help the company design a "Yank-buster" vee-twin engine. The JAP Vee Twin engine was used throughout the 1920s in several HRD models, and in the Morgan 3-Wheeler motorcar.

1931 Brough Superior JAP 1000cc Engine
976cc J.A. Prestwich Vee-Twin Engine in the Brough Superior SS100

JA Prestwich also dabbled in airplanes, chainsaws, farm implements, light-rail maintenance trucks, stationary motors for generators water pumps, or agricultural equipment, and engines for small cars such as the Morgan.

During World War II, JA Prestwich built close to a quarter-million engines for the British war effort, as well as aircraft parts and electrical components. In 1945, Villiers Engineering Ltd. of Wolverhampton took a partial stake in JA Prestwich, and in 1957 the two companies merged.

JAP Elstar Speedway Engine
Zoom: JAP Elstar Speedway Engine

Together, the JAP/Villiers alliance advertised that "jointly the two companies produce a vast range of two-stroke and four-stroke petrol engines and four-stroke diesel engines," and that these engines now powered "many of Britain's two-stroke motor cycles, scooters and three wheelers" as well as much of the industrial and agricultural equipment sold in the UK.

JA Prestwich motorcycle engines were known for their reliability and performance, which led to their use in motorcycle racing. The company's single-cylinder JAP Elstar and Rotrax engines were used in grass-track and speedway motorcycles up until their demise in 1963. The company assets were fully consolidated into the Villiers Engineering Company in 1964.

J.A. Prestwich Links

The Villiers Engineering Co. Ltd.

The Brough Superior

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