Armstrong Siddeley Jaguar Major / Panther

The Armstrong Siddeley Panther was a 27-litre 14-cylinder twin-row air-cooled radial aero engine developed by Armstrong Siddeley. First run in 1929, it was originally named the Jaguar Major.

Applications:

Armstrong Whitworth Atlas Mk II
Armstrong Whitworth A.W.XIV Starling MkII
Armstrong Whitworth A.W.16
Armstrong Whitworth A.W.35 Scimitar
Fairey Gordon
Fokker C.V
Hawker Hoopoe
Marinens Flyvebaatfabrikk M.F.11
Supermarine Air Yacht
Westland Wapiti V (first prototype)

Panther VII
Type: 14-cylinder twin-row air-cooled radial engine
Bore: 5.25 in (133.4 mm)
Stroke: 5.5 in (139.7 mm)
Displacement: 1,667 cu in (27.3 L)
Length: 64 in (1.63 m)
Diameter: 46.45 in (1.18 m)
Dry weight: 1,047 lb (475 kg)
Valvetrain: Overhead valve
Supercharger: Fully supercharged
Fuel system: Carburettor
Cooling system: Air-cooled
Power output: 638 hp (478 kW) at 2,400 rpm with 0.5 psi (3.5 kPa) boost
Compression ratio: 5.1:1
Power-to-weight ratio: 0.61 hp/lb (1.01 kW/kg)