ARTICLE: THE ANZANI SIX CYLINDER AIR-COOLED 45 HORSE POWER AERO ENGINE

Allan Sinclair

Ditsong National Museum of Military History

11 June 2019

On display at the Ditsong National Museum of Military History is an Anzani Six Cylinder Air-cooled Aero Engine which dates back to 1909 and the beginning of powered flight.

The history of powered, sustained and controlled flight began in December 1903 when a petrol-engine flying machine built by the Wright brothers was flown from Kitty Hawk in the eastern United States.  By 1908 the aviation industry had progressed with remarkable speed.

Powered flight was only possible through the development of piston engines.  Most of the early designed aircraft were powered by engines originally designed for motor cars and motorcycles. It was soon discovered that air-cooled motorcycle engines would lose power and seize up during flight while water-cooled motorcar engines proved to be heavy in the air. Aviators were compelled to develop specifically designed engines to power aircraft.

The first Anzani engines were designed from motorcycle engines. Alessandro Anzani of Courbevoie in France was a motorcycle manufacturer who designed his first purpose built aero engine in 1909. It was a three cylinder W fan type with rudimentary air-cooling and, providing it did not overheat, the engine was fairly reliable. Aviation pioneer, Louis Bleriot, used one such engine to power his Bleriot Type XI aircraft on the very first flight taken across the English Channel in December that same year.

In March 1910 Anzani launched his first two-row radial engine by merging two three cylinder motors to form a six cylinder engine.  This was essentially two three cylinder 120 degree engines bolted together on a common crankcase.  The placing three cylinders behind the other allowed equal cooling of all six cylinders. The bore of 90mm and the stroke of 200mm provided a displacement of 7 637 cubic cm and the engine produced 45 horse power (330 kW) at 1 300 revolutions per minute.  Ignition was by magneto and fuel was supplied by an up-draught carburettor. Castor oil was used for engine lubrication. The engine powered variants of French Caudron aircraft such as the Caudron – Faber Seaplane and the Type M and N fast Sports Monoplanes.  Another aircraft powered by the engine was the Dutch Pander E Training Aeroplane.

To ensure effective care and operation, general rules were produced which stated that, once the engine had been started, it was advisable to run it for several minutes with the throttle closed to afford adequate distribution of oil throughout. Only after it had been warmed up thoroughly should any acceleration take place. The rules also suggested that it was better to shut the fuel supply off first during the process of stopping the engine. This would allow the motor to die out from the charge held in the carburettor bowl which, in turn, would provide the valves with a chance to cool down and ensure that oil was distributed through the inside of the engine leaving the parts well lubricated for the next start.

The Museum’s engine underwent a restoration programme in July 2002. During the process the cylinders were stripped from the block and all components were sandblasted and cleaned.  This has enabled the engine to rotate through the turning of the propeller boss.

The display of the Anzani engine alongside other models such as the Gnome Rotary 80, the Pratt and Whitney Twin-Wasp, the Piaggio P X R, the Rolls-Royce Eagle and the BMW 109-003A provides an account of the development of engine technology during the first half of the 20thCentury.

References

Hazewinkel, H, “The Aeroplane that taught Holland How to Fly” in Aeroplane Monthly, January 1989,

Gunston, B, World Encyclopaedia of Aero Engines (London, Patrick Stevens, 1986)

Nahun, A, Flying Machines(London, Dorling Kindersley, 1990)

Website, www.BritishAnzani.co.uk/history.HTM

Correspondence with Mr Martin Osborne (Webmaster – Anzani Archive) dated June and July 2002

Article Verified by S R Mackenzie: Director