1949 Ariel Square Four Mki The Ariel Square Four was a British motorcycle designed by Edward Turner who devised the Square Four engine in 1928. Also known as the 'Squariel'. The engine was a 997cc, 4 stroke, Square Four air cooler, Ohv 8 valve. Power: 45bhp at 5500rpm. Transmission: 4 speed gearbox to chain final drive. In 1949 the cast iron cylinder head was replaced by an alloy head and barrel allowing the machine to travel at 90mph plus. The motorcycle was bought in California and has been in a private collection for many years. Before being shipped, it had a new wiring harness and head gasket. A great example in this condition including original pillion seat