Collection Item Summary:
The CD-12 development history extended over several years, and involved a number of well regarded figures in the aircraft industry. Beginning in 1915, using the design skills of Charles Kirkham, and in competition with Wright which was licensed to build the popular Hispano-Suiza engine in the United States, Curtiss, then led by John North Willys, began development of the K-12 engine.
A 224 kW (300 hp) engine weighing less than 454 kg (1,000 lb) was a great challenge. So it was not surprising that the aluminum monoblock and several other advanced features, including the reduction gearing, presented substantial problems, appearing in various stages of the development process.
Unable to overcome these difficulties, Kirkham left Curtiss in 1919. However, development continued under Arthur Nutt, and a derated CD-12, without the reduction gearing of the K-12, resulted in 1921. This further developed into the 1922 D-12, a successful engine for both racing and fighter aircraft.