Matchles motorcycle engine, 1935.
© Science Museum / Science & Society Picture Library
This four-cylinder engine was introduced in 1930 and was designed for the the Matchles 'Silver Hawk', a luxury touring motorcycle. At the time the Silver Hawk was noted for its quietnes and smoothnes of operation. All of the four cylinders are cast in one piece, with each containing the inlet and exhaust valve in a detachable cylinder head. The valves were driven by an overhead camshaft.