Deasy (United Kingdom)

Deasy Motorcar Manufacturing Co. Ltd. was established in Coventry, England, in 1906 by Captain Henry H.P. Deasy, who had previously gained recognition for his driving skills, notably with a 14hp Martini. The company was formed with the financial backing of a group of affluent associates, and it operated from a factory that had previously housed the IDF.N Motor Co. E.W. Lewis, a designer from Rover, was brought on board to develop the vehicles.

The inaugural Deasy car featured a 4.5-litre side-valve engine with en-bloc cast cylinders, marking an early adoption of this engineering practice. It also included innovative features such as a camshaft brake, full-pressure lubrication, transverse rear suspension, and an armoured wood frame. Initially, both sets of brakes operated on the rear wheels, but by 1908, a transmission brake was introduced. The lineup expanded to include larger models, such as the 8.6-litre 35 and the 12-litre 45.

Despite the initial success, relations between Deasy and Lewis deteriorated, leading to both men losing their positions by the end of 1908, although they remained involved with the company in different capacities. In 1909, J.D. Siddley joined Deasy, introducing a new range of vehicles that featured thermosyphon-cooled engines and pressed-steel frames. These models, designated as Deasy-J.D.S., included 2,918cc 14/20hp and 4,082cc 18/28hp variants, distinguishing them from the earlier Deasy Standards.

By 1911, a smaller Deasy-J.D.S. model with a 1,944cc 12hp engine was introduced. However, in 1912, the company underwent a rebranding, changing its name to Siddeley-Deasy. Captain Deasy departed around the same time, returning to Ireland, where he later became a lord justice of the Irish Court of Appeal. The company continued to produce vehicles until its eventual decline.