Overhead Cam Engines

The Bedouin

Many of the aircraft engines of the day, were redesigned to run upside down, with the 'V' at the bottom to increase the pilot's forward visibility. One of the first engines to be redesigned in this way was the Arab. The new engine was called the Bedouin. It was a water-cooled, inverted 90 degree V8, with direct drive to the propeller. The engine had a bore of 120mm and a stroke of 130mm, which gave a capacity of 12.3 litres. There were two single underside camshafts, operating three valves per cylinder (1 inlet, 2 exhaust), and two magnetos. The engine developed 200h.p. at 2,000r.p.m., but the design was not very successful and didn't go into production.

The Manitou

The Manitou was a further development of the Maori III. It had aluminium blocks instead of cast-iron, with the cylinders arranged in groups of three. The two blocks were in a 60 degree 'V', with twin overhead camshafts, operating four valves per cylinder. The propeller gear ratio was 1.54:1 and the engine weighed 1,050lbs in running condition. There were two Claudel-Hobson carburettors and two BTH magnetos. The engine developed 300h.p. at 2,000r.p.m. This was later increased to 325h.p. Only one engine was produced before the end of the war. Production was held up because of the problems the company was having with the Arab engines, and was very nearly cancelled. As far as is known the engine was fitted to just one aircraft, a Short 184. The engine was also fitted to two powerboats that were built by S.E. Saunders, of the Isle of Wight.

The engine became famous when it was fitted to Sunbeam's 350h.p. racing car. In 1922 the car was driven at the Saltburn Speed Trials by Malcolm Campbell and was very successful. Campbell was very impressed with the car and thought that it could go faster.

The Manitou as fitted to the Sunbeam racing car. Courtesy of Ray Jones.

He persuaded Coatalen to sell the car to him, so that he could compete in the car at the next years event. In the event he achieved 137.72m.p.h. for the flying kilometre. The car was sent to Boulton Paul Ltd, at Norwich, for wind tunnel tests. They streamlined the car and added a long tail to improve its performance. In September 1924 it was taken to the Pendine Sands in South Wales for an attempt on the world land speed record. This was broken on 24th September, when the car achieved a speed of 146.16m.p.h. The car returned to Pendine in 1925, and on 21st July it set a new record of 150.76m.p.h., the first time a car had exceeded 150m.p.h. The car is preserved in the National Motor Museum at Beaulieu in Hampshire. There is also a Manitou in preservation at the Black Country Living Museum, Tipton Road, Dudley.

The Manitou on display at the Black Country Living Museum.

Return to the Arab Return to Sunbeam Return to the Aircraft Section Proceed to the Saracen, Spartan and Matabele