Armstrong Siddeley Lynx Major / Cheetah
The Armstrong Siddeley Cheetah is a seven-cylinder British air-cooled aircraft radial engine of 834 cu in (13.65 lt) capacity first run in 1935 and produced until 1948. Early variants of the Cheetah were initially known as the Lynx Major.
The Cheetah was used to power many British trainer aircraft during World War II including the Avro Anson and Airspeed Oxford.
The Cheetah was developed from the earlier Lynx using the increased bore cylinders from the Armstrong Siddeley Panther but the engine retained the stroke of the Lynx. Initially only direct-drive variants were produced with later engines being made available with propeller reduction gear of various ratios. Superchargers were also available for later variants, both geared and directly driven by the crankshaft.
The basic design of the Cheetah remained unchanged from its introduction in 1935 to the last examples built in 1948. It was the first engine of its type to be certified for 1,200 hours of operational time between overhauls, with over 37,200 examples built.
Lynx V (Lynx Major)
1930, 230 hp (171 kW).
1935, 270 hp (201 kW) at 2,100 rpm.
1935, 285 hp (212 kW) at 2,425 rpm.
1935, 307 hp (229 kW) at 2,425 rpm.
1936, as Mk VI but with Mk IX cylinders.
1937, 345 hp (257 kW) at 2,425 rpm.
1938, 375 hp (280 kW) at 2,300 rpm.
345 hp (257 kW) at 2,425 rpm, geared version of Cheetah X.
Similar to Mk X, adapted for target drone aircraft.
420 hp (313 kW) at 2,425 rpm.
1948, 385 hp (287 kW) at 2,425 rpm.
385 hp (287 kW) at 2,425 rpm, carburettor modified for aerobatics.
355 hp (265 kW) at 2,425 rpm
345 hp (257 kW) at 2,425 rpm, Cheetah XV uprated to 475 hp (355 kW) at 2,700 rpm, modified constant-speed unit.
385 hp (287 kW).
1948, 385 hp (287 kW).
Airspeed Queen Wasp
CASA C-201 Alcotán
de Havilland Hawk Moth
Edgar Percival Prospector
Handley Page H.P.R.2
Kingsford Smith PL.7
Marinens Flyvebaatfabrikk M.F.8
Marinens Flyvebaatfabrikk M.F.10
Percival Provost (prototype)
Type: Seven-cylinder single-row supercharged air-cooled radial engine
Bore: 5.25 in (133 mm)
Stroke: 5.5 in (140 mm)
Displacement: 834 cu in (13.65 L)
Length: 52.8 in (1,342 mm)
Diameter: 47.6 in (1,210 mm)
Dry weight: 637 lb (289 kg)
Valvetrain: Two pushrod-actuated valves per cylinder
Supercharger: Centrifugal, 5.4:1 reduction
Fuel system: Claudel-Hobson carburettor
Fuel type: 87 octane rating petrol
Cooling system: Air-cooled
Reduction gear: No
- 338 hp (252 kW) at 2,100 rpm for takeoff
- 345 hp (257 kW) at 2,425 rpm at 7,875 ft (2,400 m)
Specific power: 0.41 hp/cu in (18.83 kW/L)
Compression ratio: 6.35:1
Specific fuel consumption: 0.45 lb/hp/hr (271 g/kW/hr)
Oil consumption: 0.24–0.45 oz/hp/hr (9–17 g/kW/hr)
Power-to-weight ratio: 0.54 hp/lb (0.89 kW/kg)