Alfa Romeo D2

The Alfa Romeo D2 was a nine-cylinder radial aircraft engine built in Italy in the early 1930s. It was designed by Vittorio Jano and was the first aircraft engine that Alfa Romeo created purely for aviation, because the company's earlier aero engines had been adapted from its car engines. About 600 were built between 1931 and 1934, and the engine was typically rated at between 240 and 270 horsepower. A supercharged derivative, the D2 C.30, had a 120 millimetre bore and a 135 millimetre stroke, displaced 13.74 litres and weighed 275 kilograms dry. The D2 powered Italian aircraft of the period, among them the Breda Ba.25, the Caproni Ca.101 and Ca.105, and the Jona J-6S.