Lynx
Armstrong Siddeley Lynx fitted to the Shuttleworth Collection's airworthy Avro Tutor
Type	Radial aero engine
National origin	United Kingdom
Manufacturer	Armstrong Siddeley
First run	1920
Number built	6,000
Developed from	Armstrong Siddeley Jaguar
Developed into	Armstrong Siddeley Cheetah

The Armstrong Siddeley Lynx is a British seven-cylinder aero engine developed by Armstrong Siddeley. It was developed as a single row version of the two-row Armstrong Siddeley Jaguar. Testing began in 1920 and 6,000 had been produced by 1939. In Italy Alfa Romeo built a 200 horsepower (150 kW) licensed version of this engine named the Alfa Romeo Lynx.^[1]

Variants

Lynx I

1920, 150 hp (110 kW).

Lynx II

1920, 184 hp (137 kW).

Lynx III

1924, 200 hp (150 kW).

Lynx IV

1929, 180 hp (130 kW).

Lynx IVA

1930, 188 hp (140 kW).

Lynx IVC

1929, 208 / 225 hp (155 / 168 kW).

Lynx IV(G)

1929, Geared propeller drive.

Lynx IV(MOD)

1929, 188 hp (140 kW), reconditioned and modified Lynx IV.

Lynx IV(S)

1928, 200 hp (150 kW), fully supercharged.

Lynx V (Lynx Major)

1930, increased bore and stroke, name changed from Lynx V to Lynx Major then Cheetah. Effectively half a Panther^[2]

Piaggio P.II

Licence production in Italy by Piaggio.

Applications

Airspeed Courier Airspeed Envoy Albatros L 68 Avro 504 Avro 618 Ten Avro Avocet Avro 641 Commodore Avro 626 Avro 642/4m Eighteen Avro Sea Tutor Avro Tutor BAT Bantam Blackburn Lincock Boulton Paul Bittern Canadian Vickers Vanessa Canadian Vickers Varuna Canadian Vickers Vedette Cierva C.8 de Havilland Hawk Moth

Fairchild FC-2 Fokker C.VII Fokker F.VIIA Gloster Grouse Messerschmitt M 18 Morane-Saulnier MS.230 Nieuport-Delage NiD 39 Larynx Parnall Parasol Raab-Katzenstein RK-26 Wackett Warrigal Saro Cloud Saro Cutty Sark Supermarine Seamew Vickers Vireo VL Tuisku Westland Wagtail

Alfa Romeo Lynx

• Breda Ba.19
• Breda Ba.25
• IMAM Ro.10

Survivors

• Avro Tutor, K3215, powered by a Lynx IV, flies regularly at the Shuttleworth Collection and can be viewed in the museum at other times.^[3]

Specifications (Lynx IV)

Data from Lumsden^[4]

General characteristics

• Type: 7-cylinder air-cooled radial engine
• Bore: 5.0 in (127 mm )
• Stroke: 5.5 in (140 mm)
• Displacement: 756 cu in (12.4 L)
• Length: 45.6 in (1,158 mm)
• Diameter: 42 in (1,067 mm)
• Dry weight: 525 lb (238 kg )

Components

• Valvetrain: Overhead valve, 2 valves per cylinder
• Fuel system: Carburettor
• Cooling system: Air-cooled

Performance

• Power output: 187 hp (139 kW) at 1,700 rpm cruise / 215 hp (160 kW) at 1,900 rpm max
• Power-to-weight ratio: 0.35 hp/lb (0.6 kW/kg)