OS engines


Type 1 photo

In 1936, Shigeo Ogawa set up his original machine-shop, making model steam engines. In the same year, at the suggestion of an American buyer, Paul Houghton, the 1.6 cc O.S. Type-1 miniature gasoline engine was constructed. Some 200 production models were subsequently exported under the brand name 'Pixie.'

Type 3 photo

The Type-1 followed American model i.c. engine design of the time. It was succeeded, in 1937, by the much larger (6.92 cc) Type-2 and, in 1938, by the 7.45 cc Type-3, an original O.S. design which set the ground work for future O.S. engine development.
MAX-1 15

Max 15 photo

The first of a long line of O.S. 'MAX' engines, the MAX-1 29 and MAX-1 35 appeared in 1954, followed by the MAX-1 15 in 1955. In 1956, a MAX-1 15 powered model, flown by Ronald Draper, won the official (FAI) World Free Flight Championship held in England. This drew worldwide attention to O.S. engines and became the turning point that led, eventually, to O.S. prominence in the world market.

Wankel photo

This unique rotary combustion engine received international acclaim as the world's first production model miniature Wankel type power unit. Refined over many years of development, it is smooth running and powerful and remains the only regular production model engine of this type.

40 SR photo

The special O.S. designed machinery built for the complex high-precision machining operations essential to the success of the O.S. Rotary Engine, raised O.S. production technology to new levels. This proved invaluable in the manufacture of all subsequent O.S. engines, beginning with the high performance 6.5 cc Schnuerle-scavenged MAX-40SR of 1973.

FS 60 photo

This 10 cc overhead-valve engine was the first volume-produced four-stroke-cycle model aircraft power unit. Very much quieter than equivalent two-stroke engines, it was widely accepted for its "environmental friendliness" and resulted in many other manufacturers introducing four-stroke engines - though not all were as quiet.

FT-120 photo

This 20 cc four-stroke was the first O.S. twin cylinder engine and was the starting point for the current range of superb multi-cylinder scale-type power units, including horizontally-opposed four-cylinder and radial type five-cylinder models. Ideal for large scale aircraft, they are flexible and outstandingly smooth running.


A special high-performance version of the 20 cc single cylinder FS-120S four-stroke, this engine has the addition of an O.S. designed Roots type supercharger: the very first time that a genuine supercharger has been fitted to a production model engine. Mr. Giichi Naruke won the 1995 FAI F3A (aerobatics) World Championship using one of these engines.