Square Four Mk I Original Miles, Restored

1950 Ariel Square Four Mk I The Square Four is a motorcycle produced by the British Motorcycle manufacturer. Ariel between 1931 and 1959. designed by Edward Turner. who devised 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 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. Engine: 997 cc. 4-stroke. square four. air-cooled. OHV. 8-valve Power: 45 bhp (34 kW) @ 5. 00 rpm Transmission: 4-speed gearbox to chain final drive Wheelbase: 56 inches (1. 22 mm) Fuel Capacity: 5 imp gal (23 l; 6. 0 US gal) Total # produced: Mk I - 1000cc - 1949 - 1953: 3. 22 In the years after the end of WWII the 1000cc Square Four was advertised as a powerful sporting solo ride. Advertisements proclaimed "Spectacular acceleration". "Rockets from a standstill" and "Whispering Wildfire". In 1949 the cast iron engine was redesigned with an all alloy block and head improving cooling. This reduced weight by 33 lbs with resulting improvements in handling and acceleration. The Mark I was capable of 90 mph-plus. This all alloy version was later dubbed the 4G Mk I when the redesigned Mk II was phased into production in 1953. Production of the Mk I ended in 1953. We are pleased to offer for sale this 1950 Ariel Square Four. a fully restored "show or go" example of this fine British Motorcycle.