Curtiss Model S, In-line 6 Engine

Type: Reciprocating, 6 cylinders, in-line, water-cooled

Power rating: 52.2 kW (70 hp) at 1,325 rpm

Displacement: 8.24 L (502.64 cu in)

Bore and Stroke: 102 mm (4 in.) x 127 mm (5 in.)

Weight: 129 kg (285 lb)

Among the most successful early engines marketed in the United States were those designed and built by aviation pioneer and inventor Glenn H. Curtiss in his factory in Hammondsport, New York. The earliest Curtiss designed engines powered his racing motorcycles. The first Curtiss aircraft engine, a 5.2 kW (7 hp) air cooled, V-twin, powered a small dirigible in 1904.

In 1912, the Curtiss Company introduced a new six-cylinder, in-line water-cooled engine known as the Model S. Designed by Charles B. Kirkham, an associate of Curtiss for a number of years who later became the company’s chief engineer, only six Model S engines are believed to have been produced, and the U.S. Navy purchased five. This was the first Curtiss engine to depart from the single rocker arm operating both intake and exhaust valves since the Silver Dart aircraft engine of 1908.