The Caffort 12Aa was a 12-cylinder,

horizontally-opposed A flat engine is a piston engine where the cylinders are located on either side of a central crankshaft. Flat engines are also known as horizontally opposed engines, however this is distinct from the less common opposed-piston engine design, ...

, piston

aircraft engine An aircraft engine, often referred to as an aero engine, is the power component of an aircraft propulsion system. Aircraft using power components are referred to as powered flight. Most aircraft engines are either piston engines or gas turbin ...

designed and built in

France France, officially the French Republic, is a country located primarily in Western Europe. Overseas France, Its overseas regions and territories include French Guiana in South America, Saint Pierre and Miquelon in the Atlantic Ocean#North Atlan ...

during the latter half of the 1920s.

Design and development

Having produced automobile and aircraft engine parts under contract during

WWI World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a global conflict between two coalitions: the Allies (or Entente) and the Central Powers. Fighting took place mainly in Europe and th ...

, the Caffort brothers set about the task of producing their own aircraft engine, under a licence from "Bertrand-Solanet", of whom there is very little known, leaving the Caffort 12Aa as a testament. Built largely from cast

Aluminium alloy An aluminium alloy ( UK/IUPAC) or aluminum alloy ( NA; see spelling differences) is an alloy in which aluminium (Al) is the predominant metal. The typical alloying elements are copper, magnesium, manganese, silicon, tin, nickel and zinc. There ...

s the 12Aa was a geared engine with four

Zenith The zenith (, ) is the imaginary point on the celestial sphere directly "above" a particular location. "Above" means in the vertical direction (Vertical and horizontal, plumb line) opposite to the gravity direction at that location (nadir). The z ...

carburetors supplying mixture to the lower intake valves. Four camshafts at the corners of the crankcase operated two intake valves and two exhaust valves per cylinder, also driving oil pumps and other accessories. The four magnetos were mounted on transverse shafts driven from the crankshaft at the front of the engine. A single water pump was mounted on the rear cover, driven directly from the crankshaft.

Design and development

Specifications (12Aa)

References

Further reading