Armstrong Siddeley Serval / Double Mongoose
The Serval was a ten-cylinder, double-row, air-cooled radial piston engine. It was developed from the Armstrong Siddeley Mongoose and was, more or less, two Mongooses built around a single crankcase. In fact, it first appeared as the Double Mongoose in May 1928.
Built in several variants, power output was about 340 hp (254 kW).
Serval I initially Double Mongoose
(1931) 340 hp.
(1932) 310 hp.
(1933) 340 hp.
Armstrong Whitworth Atalanta
Canadian Vickers Vancouver
Type: 10-cylinder double-row radial
Bore: 5 in (127 mm)
Stroke: 5.5 in (139.7 mm)
Displacement: 1,080 cu in (17.7 L)
Length: 54.25 in (1,378 mm)
Diameter: 45.6 in (1,158 mm)
Dry weight: 714 lb (324 kg)
Valvetrain: Overhead poppet valves
Fuel type: 77 Octane petrol
Cooling system: Air-cooled
Reduction gear: Direct drive, Left hand tractor
Power output: 340 hp at 2,000 rpm at sea level
Compression ratio: 5:1
Power-to-weight ratio: 0.47 hp/lb