Sunbeam Dyak

Dyak
Type	Piston inline aero-engine
Manufacturer	Sunbeam
First run	May 1918
Major applications	Avro 504
Variants	Sunbeam Pathan

The Sunbeam Dyak was a British inline six-cylinder, water-cooled, twin updraught carburettor engine.

It had an aluminium sump, block and cylinder head, and is an overhead camshaft design with two valves per cylinder. The output was approximately 106 horsepower (79 kW). One was fitted to the first Queensland and Northern Territory Aerial Services (QANTAS) aircraft (an Avro 504K) and was fitted in Australia by the Australian Aircraft & Engineering Co. Ltd. at Mascot, New South Wales. The engine was started by turning a geared crank handle in the cockpit. The diesel-powered Sunbeam Pathan was developed from this engine.

Specifications (Dyak)

Data from Lumsden^[1]

General characteristics

• Type: 6-cylinder, upright, inline engine
• Bore: 4.72 in (120 mm)
• Stroke: 5.12 in (130 mm)
• Displacement: 538.26 cu in (8.8 L)
• Dry weight: 399 lb

Components

• Valvetrain: Overhead camshaft, two valves per cylinder
• Cooling system: Liquid-cooled
• Reduction gear: Direct drive, left-hand tractor

Performance

• Power output: 100 hp at 1,200 rpm (takeoff power)
• Compression ratio: 5:1

See also

Comparable engines

• Benz Bz.II

Related lists

• List of aircraft engines

References

Notes

1. Lumsden 2003, p. 228.

Bibliography

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

External links

• "Sunbeam Overhead Cam Engines". Wolverhampton Museum of Industry. Archived from the original on 2008.