Armstrong Siddeley Puma
The Siddeley Puma was a British aero engine developed towards the end of World War I and produced by Siddeley-Deasy. The first engines left the production lines of Siddeley-Deasy in Coventry in August 1917, production continued until December 1918. At least 4,288 of the 11,500 ordered engines were delivered, orders were cancelled following the Armistice. Production was continued under the name Armstrong Siddeley Puma when the manufacturer was bought by Armstrong Whitworth and became Armstrong Siddeley.
The engine was based on a previous B.H.P engine.
The Puma engine was used in the British World War I bomber aircraft, the Airco D.H.9. In use it proved to be highly troublesome, making the aircraft significantly inferior to the type it replaced. The engine was also installed untidily, with the cylinder heads protruding. The D.H.9, as a type, was improved by replacing the Puma engine with the Liberty 12 to make the D.H.9A.
The unit was used in the first prototype of the Airco DH.10 in a twin-engined pusher configuration but as performance was unsatisfactory, alternative engines were used in a subsequent prototype of the type and production models.
Short Silver Streak (1920)
Type: 6-cylinder water-cooled inline aircraft piston engine
Bore: 5.71 in (145 mm)
Stroke: 7.48 in (190 mm)
Displacement: 1,149 in³ (18.832 L)
Length: 69.9 in (1,175 mm)
Width: 24 in (610 mm)
Height: 43.6 in (1,107 mm)
Dry weight: 645 lb (293 kg)
Fuel system: Carburettor
Cooling system: Water-cooled
250 hp (186 kW) at 1,400 rpm for takeoff
265 hp (198 kW) at 1,500 rpm for short-term maximum power
Specific power: 0.23 hp/in³ (10.5 kW/L)
14 US gal/h (54 L/h) at cruise
67 US gal/h (258 L/h) at short-term maximum power
Power-to-weight ratio: 0.41 hp/lb (0.67 kW/kg)