The Armstrong Siddeley Leopard was a British 14-cylinder twin-row air-cooled radial aero engine developed in 1927 by Armstrong Siddeley. It was the most powerful radial engine in the world when introduced.
Variants:
Leopard I 700 hp, medium supercharged. Direct drive propeller.
Leopard II 700 hp, geared epicyclic drive.
Leopard III 800 hp, two-valve cylinder head, direct drive.
Leopard IIIA 800 hp, geared epicyclic drive.
Applications: Blackburn Iris Junkers Ju 52 Hawker Dantorp Hawker Horsley
Specifications:
Leopard I Type: 14-cylinder twin-row air-cooled radial engine Bore: 6.0 in (152.4 mm) Stroke: 7.5 in (190.5 mm) Displacement: 2,970 cu in (48.6 L) Length: 60.85 in (1546 mm) Diameter: 58 in (1473 mm) Dry weight: 1,466 lb (665 kg) Valvetrain: Overhead valve, four valves per cylinder Fuel type: Petrol Cooling system: Air-cooled Power output: 700 hp (522 kW) at 1,650 rpm at sea level Compression ratio: 5.00:1 Fuel consumption: 45 gal/hr (169 l/hr) at cruise speed Power-to-weight ratio: 0.47 hp/lb