Built at Bristol by Brazil-Straker under the direction of Roy Fedden, the Mercury featured an unusual crankshaft and connecting rod arrangement that dispensed with the more normal design of a single master rod linking to individual rods for each cylinder. It was said to run well without vibration and set an unofficial time to climb record while fitted to a Bristol 21A Scout F.1, the aircraft achieving 10,000 ft (3,000 m) in 5.4 minutes and 20,000 ft (6,000 m) in 16.25 minutes.^[1]

An Admiralty order for 200 engines was placed in 1917 but was later cancelled by Lord Weir due to the end of World War I, it is also stated that Lord Weir had a preference for the ABC Dragonfly.^[2]

The name was re-used by Fedden for the later nine-cylinder Bristol Mercury radial engine.

• Bristol Scout F

Data from Lumsden.^[1]

General characteristics

• Type: 14-cylinder air-cooled two-row radial engine
• Bore: 4.375 in (111 mm)
• Stroke: 5.8 in (147.6 mm)
• Displacement: 1,223 cu in (20 L)

Components

• Valvetrain: 2 valves per cylinder, poppet valve
• Fuel type: Petrol
• Cooling system: Air-cooled

Performance

• Power output: 347 hp (259 kW) at 2,000 rpm at sea level
• Compression ratio: 5.3:1

Comparable engines

• Armstrong Siddeley Jaguar
• Gnome-Rhône 14M
• Pratt & Whitney R-1535 Twin Wasp Junior

Related lists

• List of aircraft engines

Notes edit

Bibliography edit

• "The Cosmos Aero Engines". Flight. XI (27): 869–871. July 3, 1919. No. 549. Archived from the original (PDF) on 3 June 2016. Retrieved January 12, 2011. Contemporary article on Cosmos Engineering's air-cooled radial engines. Photos of the Mercury are on page 869, and a short technical description is on page 871.
• Flight magazine, 22 May 1919 - Flightglobal.com, archived on 11 October 2012
• Flight magazine, 12 February 1960 - Flightglobal.com, archived on 11 October 2012
• Cosmos Mercury at Aviationarchive.org