The Sunbeam Sikh was a large slow running V-12 piston engine, intended to power airships, under development at the time of the
Armistice.
Design and development
At the end of the
First World War there was an expectation that Britain would continue the development of airships to provide air travel throughout the
British Empire. To power the expected airships Louis Coatalen designed the large Sikh V-12 engine delivering at only 1,400 rpm, from 64.13 litre (3,913 in
3) displacement in a 60-degree
V12 V12 or V-12 may refer to:
Aircraft
* Mil V-12, a Soviet heavy lift helicopter
* Pilatus OV-12, a planned American military utility aircraft
* Rockwell XFV-12, an American experimental aircraft project
* Škoda-Kauba V12, a Czechoslovak experim ...
configuration, with six valves per cylinder operated by rockers actuated by overhead camshafts.
Bench testing of this impressive engine began in 1919, passing
Air Ministry acceptance tests in time for one to be displayed at the
1919 Paris Aero Salon
Events
January
* January 1
** The Czechoslovak Legions occupy much of the self-proclaimed "free city" of Pressburg (now Bratislava), enforcing its incorporation into the new republic of Czechoslovakia.
** HMY ''Iolaire'' sinks off the c ...
and the
1920 Olympia Aero Show
Nineteen or 19 may refer to:
* 19 (number), the natural number following 18 and preceding 20
* one of the years 19 BC, AD 19, 1919, 2019
Films
* ''19'' (film), a 2001 Japanese film
* ''Nineteen'' (film), a 1987 science fiction film
Music ...
where it generated much interest, due to its size, but no production orders.
Competition to power what little airship production there was came from the
Rolls-Royce Condor
The Rolls-Royce Condor aircraft piston engine was a larger version of the Rolls-Royce Eagle developing up to 675 horsepower (500 kW). The engine first ran in 1918 and a total of 327 engines were recorded as being built.
Variants
''Note:'' ...
and the
Napier Cub. Development work continued till the engine produced by 1923.
To power smaller airships or
Blimps, Coatalen used one cylinder bank to create the Sikh II aka Semi-Sikh, a straight six-cylinder developing 400 to 425 hp (298 to 317 kW) @ 1,400 rpm.
As with the Sikh, the market for airship engines dried up after the war, so no production Sikh II engines were built.
In the late 1920s large airships were in favour again, so Coatalen revised the Sikh and developed the Sunbeam Sikh III for the
R100 and
R101 airship families.
Retaining the bore, stroke and displacement of the earlier engine, detail refinements included five valves per cylinder and enclosed valve-gear. The Sikh III was displayed at the 1929 Olympia Aero Show, generating interest due to its large size, weight and power. After the
R101 disaster the large Empire airships were abandoned, and the airship market for Sunbeam engines disappeared for a second time, leaving the Sikh III with no orders.
No Sikh engines of any version were sold.
Variants
;Sikh
:The original 800 hp airship engine intended for use by airships to be developed after the war, which were cancelled.
;Sikh II
:Following his previous practise Coatalen developed a straight six version of the Sikh, using a single bank of cylinders. Also intended for airships to be developed after the war, the Sikh II was cancelled when the airships did not materialise.(32.1L / 1,957 in
3)
;Semi-Sikh
:Alternative name for the Sikh II.
;Sikh III
:In the late 1920s, renewed interest in airships, which spawned the Empire Airship programme, also encouraged development of engines to power the airships with. The Sikh III was one of these; closely following the Sikh in construction, major differences included two inlet valves instead of three and enclosed valve-gear.
Specification (Sikh III)
References
Bibliography
* Brew, Alec. ''Sunbeam Aero-Engines''. Airlife Publishing. Shrewsbury.
External links
*
{{Sunbeam aeroengines
Sikh
Sikhs ( or ; pa, ਸਿੱਖ, ' ) are people who adhere to Sikhism, Sikhism (Sikhi), a Monotheism, monotheistic religion that originated in the late 15th century in the Punjab region of the Indian subcontinent, based on the revelation of Gu ...
1920s aircraft piston engines
Airship engines