Edward Turner

Edward Turner
Turner, on the occasion of his retirement in 1967, at a private function for BSA Triumph executives
Personal details
Born	(1901-01-24)24 January 1901 Camberwell, United Kingdom
Died	15 August 1973(1973-08-15) (aged 72) Dorking, United Kingdom
Spouse(s)	Edith Webley (1929–1939) (her death) Shirley Watts (1952–1965?)(divorced)

Edward Turner (24 January 1901 – 15 August 1973) was an English motorcycle designer. He was born in Camberwell in the London Borough of Southwark, on the day King Edward VII was proclaimed King. In 1915, Turner had his first ride on a motorcycle, a Light Tourist New Imperial.

On 16 April 1925 "The Motor Cycle" published drawings by Turner of an OHC single he had designed, using a series of vertically stacked gears to drive the overhead camshaft. A subsequent redesign used bevel gears to drive a vertical camshaft, operating the valves through rockers. The only shared aspects of the two designs were the bore and stroke, 74 mm × 81 mm (2.9 in × 3.2 in), with the barrel being sunk into the crankcases. The head could be removed from either design complete with undisturbed valve gear.

Turner built his first bike in 1927, using his second design, a 350 cc OHC single. The Motor Cycle published a photograph of Turner's patented engine, mounted in his motorcycle called the Turner Special. The Special was registered for road use with the London County Council as YP 9286. It used Webb forks, and a three-speed Sturmey-Archer gearbox.

By now, living at various addresses in Peckham and East Dulwich, in the London Borough of Southwark and running Chepstow Motors, a Peckham Road motorcycle shop with a Velocette agency, Turner conceived the Square Four engine in 1928. At this time he was looking for work, showing drawings of his engine design to motorcycle manufacturers. The engine was essentially a pair of 'across frame' OHC parallel twins joined by their geared central flywheels, with a one-piece four-cylinder block (or Monobloc) and single head. The idea for the engine was rejected by BSA, but adopted by Ariel. Thus it became the Ariel Square Four, and not the BSA Square Four. Turner was then invited by Jack Sangster to join Ariel.