Valveless

David Brown & Sons' (DBS) 1914 Valveless at Tolson Museum
Engine of a "Valveless" car [1]
Patent Drawing by Ralph Lucas in US Patent US952706A

The Valveless was an English automobile manufactured, after lengthy development, from 1908 until 1915 in Huddersfield, Yorkshire. The successor to the Ralph Lucas Valveless, the car marked the entry of the David Brown & Sons group into the manufacture of motors. Its engine was a 20 or 25 hp duplex two-stroke model which was advertised as having "only six working parts"; these included two pistons, two connecting rods, and two crankshafts, which were geared together and counter-rotated. This is a type of engine configuration known as a split single since it is effectively a single cylinder split into two.

  1. ^ The Autocar (c. 1919). Autocar Handbook (Ninth ed.). London: Iliffe & Sons. p. 46.