Armstrong Siddeley Jaguar

Jaguar
Armstrong Siddeley Jaguar IV
Type	Radial engine
National origin	United Kingdom
Manufacturer	Armstrong Siddeley
First run	21 June 1922

The Armstrong Siddeley Jaguar was an aero engine developed by Armstrong Siddeley. The Jaguar was a petrol-fuelled air-cooled 14-cylinder two-row radial engine design. The Jaguar III was first used in 1923, followed in 1925 by the Jaguar IV and in 1927 by the Jaguar VI.

Design and development

The Jaguar was developed from the Royal Aircraft Factory RAF.8 design proposal of 1917, and was engineered to use a gear-driven supercharger. First run on 21 June 1922 initial performance was not as expected, as a result the bore was increased to 5.5 in (139.7 mm), with all variants after the Jaguar I using this dimension. Throughout its career the Jaguar suffered from vibration due to a lack of a crankshaft centre bearing.^[1]

The most powerful version of the engine, the Jaguar VIC, produced a maximum of 490 hp (365 kW) on takeoff at 1,950 rpm and weighed 910 lb (413 kg).^[2] The later Lynx was designed using one row of Jaguar cylinders.^[3]

Variants

Jaguar I

1922, 300 hp.

Jaguar II

1923, 385 hp, increased bore, capacity 1,512.5 cu in (24.8 L).

Jaguar III

1923, 385 hp.

Jaguar IIIA

1923, 380 hp.

Jaguar IV

1925, 385 hp, twin carburettors

Jaguar IVA

420 hp, Geared propeller drive.

Jaguar IVC

1928, 400 hp, revised connecting rod design, enclosed valve gear.

Jaguar IV(S)

1925, 365 hp, fully supercharged.

Jaguar V

1928.

Jaguar VI

1927.

Jaguar VI(S)

1928, supercharged version of Jaguar VI.

Jaguar VIC

1927, 470 hp, geared propeller drive version of Jaguar VI.

Jaguar VID

1928.

Jaguar VIIA

1929, 400 hp, fully supercharged.

Jaguar VIII

1928, 405 hp, fully supercharged, geared propeller drive

Applications

Airco DH.4 Airco DH.9 Armstrong Whitworth Ajax Armstrong Whitworth Aries Armstrong Whitworth Argosy Armstrong Whitworth Atlas Armstrong Whitworth Siskin Armstrong Whitworth Starling Armstrong Whitworth Wolf Avro 642 Blackburn Airedale Blackburn C.A.15C Blackburn Turcock Boulton Paul P.71 De Havilland Dormouse

De Havilland DH.50 De Havilland Giant Moth De Havilland Hyena Fairey Ferret Fairey Flycatcher Fokker C.V Fokker D.XVI Gloster Gnatsnapper Gloster Grebe Handley Page Hampstead Hawker Danecock Hawker Hawfinch Hawker Hoopoe Hawker Woodcock

Larkin Lascowl Martinsyde ADC 1 Nieuport Nighthawk Parnall Plover RAAF Experimental Section Warrigal II Supermarine Air Yacht Supermarine Nanok Supermarine Southampton Vickers Vellore Vickers Vespa Vickers Viastra Vickers Vimy Trainer Westland Wapiti Westland Weasel

Engines on display

A preserved Armstrong Siddeley Jaguar is on public display at the Science Museum (London).

Specifications (Jaguar I)

Sectioned Armstrong Siddeley Jaguar on display at the Science Museum (London)

Data from Lumsden^[4]

General characteristics

• Type: 14-cylinder 2-row radial engine
• Bore: 5 in (127 mm)
• Stroke: 5 in (127 mm)
• Displacement: 1,375 cu in (22.5 L)
• Length: 41 in (1,041 mm)
• Diameter: 43 in (1,092 mm)
• Dry weight: 710 lb (322 kg)

Components

• Supercharger: Gear driven
• Fuel system: Carburettor
• Cooling system: Air-cooled

Performance

• Power output: 680 hp (507 kW)
• Compression ratio: 5:1
• Fuel consumption: 19 gal/hr (71 L/hr) at cruise
• Power-to-weight ratio: 0.95 hp/lb (1.6 kW/kg)

See also

Related development

• Armstrong Siddeley Lynx

Comparable engines

• Cosmos Mercury

Related lists

• List of aircraft engines

References

Notes

1. Lumsden 2003, p. 63.
2. Lumsden 2003, Part 4 - Engine Performance Figures.
3. Gunston 1989, p. 18.
4. Lumsden 2003, pp. 63–66.

Bibliography

• Lumsden, Alec. British Piston Engines and their Aircraft. Marlborough, Wiltshire: Airlife Publishing, 2003. ISBN 1-85310-294-6.

External links

• Virtual aviation museum
• The Siddeley "Jaguar"s' 17,000 Miles - a 1926 Flight article on the Jaguar's endurance during an London-Cape Town-London flight by Alan Cobham