avia.wikisort.org - Engine

The Alvis Leonides Major was a British air-cooled 14-cylinder radial aero engine developed by Alvis from the earlier nine-cylinder Leonides.[1]

Leonides Major
Type	Radial engine
National origin	United Kingdom
Manufacturer	Alvis
Major applications	Westland Whirlwind
Developed from	Alvis Leonides

Design and development

In 1951 Alvis started development of a 14-cylinder, two row radial of 1,118 cu in (18.3 L) displacement, based on the Leonides. Certification covered the Mk. 702/1 for aeroplanes at 875 hp (652 kW) and the 751/1 for helicopters at 850 hp (630 kW). The only numerous model of the Major was the Mk. 755/1, a medium supercharged, de-rated, obliquely mounted direct-drive and fan cooled engine fitted to the Westland Whirlwind Mks. 5, 6, 7 and 8.[2]

Variants

Data from:British Piston Engines and their Aircraft.[3]

Leonides Major 702/1

850–875 hp (634–652 kW) for aeroplanes, also known as A.LE.M.1-1 in Air Ministry

Leonides Major 751/1

850 hp (630 kW) for helicopters, also known as A.LE.M.1-2

Leonides Major 755/1

780 hp (580 kW) for helicopters in a 35° canted mounting, also known as A.LE.M.1-6 and as Mk.155 in civil aircraft

Leonides Major 755/2

780 hp (580 kW) for helicopters in a vertical mounting, also known as A.LE.M.1-6 and as Mk.160 in civil aircraft

Applications

• Bristol Type 173 Mk3 – 2x 755/1 (Mk.155) 780 hp (580 kW); 2x 755/2 (Mk.160) 780 hp (580 kW)
• Handley Page HPR.5 Herald – four 850 hp (630 kW) 702/1
• Westland Whirlwind 1x 755/1 (Mk.155) or 1x 755/2 (Mk.160) 780 hp (580 kW)

Specifications (Leonides Major 702/1)

Data from Jane's All the World's Aircraft 1956-57.[4]

General characteristics

• Type: 14-cylinder twin-row air-cooled radial piston engine, geared down and supercharged
• Bore: 4.80 in (122 mm)
• Stroke: 4.41 in (112 mm)
• Displacement: 1,118 cu in (18.32 L)
• Length: 70.9 in (180 cm)
• Diameter: 38.9 in (99 cm)
• Dry weight: 1,200 lb (540 kg) (dry)

Components

• Valvetrain: 2 sodium cooled valves per cylinder, driven by 2 cam discs
• Supercharger: Single speed single stage driven at 6.5:1
• Fuel system: Fuel injection, low pressure via Hobson or SU pump
• Fuel type: 100/130 octane
• Oil system: Dry sump, pressure and scavenge pumps
• Cooling system: Air-cooled
• Reduction gear: Farman type epicyclic, ratio 0.533:1
• 2 spark plugs per cylinder, twin BTH C.14.C/1 magnetos

Performance

• Power output: (international rating) 860 hp (642 kW) at 1,500 ft (457 m)
• Compression ratio: 6.8:1
• Fuel consumption: 60 imp gal (72 US gal; 270 l) per hour (at maximum continuous power)
• Oil consumption: 6-12 pint/h (3.4-6.8 L/h)

See also

Related development

• Alvis Leonides

Comparable engines

• Pratt & Whitney R-1535

Related lists

• List of aircraft engines

References

На других языках

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[de] Alvis Leonides

Der Alvis Leonides ist ein luftgekühlter Sternmotor mit neun Zylindern. Er wurde in seiner ersten Ausführung von dem britischen Hersteller Alvis von 1937 an gefertigt. Das Unternehmen baute zu dieser Zeit französische Motoren von Gnôme et Rhône in Lizenz.

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- [en] Alvis Leonides Major

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[it] Alvis Leonides Major

L'Alvis Leonides Major era un motore aeronautico radiale 14 cilindri a doppia stella raffreddato ad aria prodotto dall'azienda britannica Alvis Car and Engineering Company Ltd negli anni cinquanta.

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