Napier Lion
Encyclopedia
The Napier Lion was a 12-cylinder broad arrow configuration
W engine
A W engine is a type of reciprocating engine arranged with its cylinders in a configuration in which the cylinder banks resemble the letter W, in the same way those of a V engine resemble the letter V....
aircraft engine
Aircraft engine
An aircraft engine is the component of the propulsion system for an aircraft that generates mechanical power. Aircraft engines are almost always either lightweight piston engines or gas turbines...
built by Napier & Son
Napier & Son
D. Napier & Son Limited was a British engine and pre-Great War automobile manufacturer and one of the most important aircraft engine manufacturers in the early to mid-20th century...
starting in 1917, and ending in the 1930s. A number of advanced features made it the most powerful engine of its day, and kept it in production long after contemporary designs had stopped production. It is particularly well known for its use on a number of racing designs, in aircraft, boats, and cars.
Design and development
Early in in the First World War Napier were contracted to build aero engines to designs from other companies: initially a Royal Aircraft FactoryRoyal Aircraft Establishment
The Royal Aircraft Establishment , was a British research establishment, known by several different names during its history, that eventually came under the aegis of the UK Ministry of Defence , before finally losing its identity in mergers with other institutions.The first site was at Farnborough...
model and then Sunbeams. Both proved to be rather unreliable, and in 1916 Napier decided to design their own instead. Reasoning that the key design criteria were high power, light weight, and low frontal area, the engine was laid out with its 12 cylinders in what they called a "broad arrow"—three banks of four cylinders sharing a common crankcase. This suggested the design's first name, the Triple-Four. Today these designs, of which there were only a few, are sometimes referred to as a W-block, although that designation applies more correctly to an engine in which a common crankcase is shared by not merely three but in fact four rows of cylinders (since a "W" is made of four lines or bars). The engine was also advanced in form, the heads using four valves per cylinder with twin overhead camshaft
Camshaft
A camshaft is a shaft to which a cam is fastened or of which a cam forms an integral part.-History:An early cam was built into Hellenistic water-driven automata from the 3rd century BC. The camshaft was later described in Iraq by Al-Jazari in 1206. He employed it as part of his automata,...
s on each bank of cylinders and a single block being milled from aluminium
Aluminium
Aluminium or aluminum is a silvery white member of the boron group of chemical elements. It has the symbol Al, and its atomic number is 13. It is not soluble in water under normal circumstances....
instead of the more common separate-cylinder steel construction used on almost all other designs.
Under A. J. Rowledge
Arthur Rowledge
Arthur John Rowledge MBE, FRS was an English engineer who designed the Napier Lion aero engine and was a key figure in the development of the Rolls-Royce Merlin.-Career:...
, the design of the newly-renamed Lion was completed in 1917, and the first hand-built prototypes ran later that year. It was fitted to a de Havilland
De Havilland
The de Havilland Aircraft Company was a British aviation manufacturer founded in 1920 when Airco, of which Geoffrey de Havilland had been chief designer, was sold to BSA by the owner George Holt Thomas. De Havilland then set up a company under his name in September of that year at Stag Lane...
built DH.9
Airco DH.9
The Airco DH.9 - also known after 1920 as the de Havilland DH.9 - was a British bomber used in the First World War...
in early 1918, proving to have many cooling problems. In addition the milled block turned out to be difficult to build with any accuracy and they reverted to separate cylinders, although they remained aluminium. Both of these problems were worked out by the middle of the year and the engine entered production in June 1918. The first Lion I versions delivered 450 hp
Horsepower
Horsepower is the name of several units of measurement of power. The most common definitions equal between 735.5 and 750 watts.Horsepower was originally defined to compare the output of steam engines with the power of draft horses in continuous operation. The unit was widely adopted to measure the...
(335 kW) from their 24 litre
Litre
pic|200px|right|thumb|One litre is equivalent to this cubeEach side is 10 cm1 litre water = 1 kilogram water The litre is a metric system unit of volume equal to 1 cubic decimetre , to 1,000 cubic centimetres , and to 1/1,000 cubic metre...
s. It then took the crown of the most powerful engine from the Liberty L-12
Liberty L-12
The Liberty L-12 was a 27 litre water-cooled 45° V-12 aircraft engine of 400 horsepower designed both for a high power-to-weight ratio and for ease of mass production.-History:...
, the excellent US wartime design of 400 hp (300 kW).
As the most powerful engine available (particularly after a turbocharger
Turbocharger
A turbocharger, or turbo , from the Greek "τύρβη" is a centrifugal compressor powered by a turbine that is driven by an engine's exhaust gases. Its benefit lies with the compressor increasing the mass of air entering the engine , thereby resulting in greater performance...
became an option in 1922), the Lion went on to be a huge commercial success. Through the years between the wars the Lion was ubiquitous, and Napier manufactured little else. They stopped making cars in 1925, and little thought was given to replacing their world-famous product. Between the wars it powered over 160 different types of aircraft.
Engine tuning
Engine tuning is the adjustment, modification or design of internal combustion engines to yield optimal performance, to increase an engine's power output, economy, or durability....
racing versions the engine could reach 1,300 hp (970 kW), and it was used to break a host of world records: height, air speed, and long distance in aircraft, water speed (delivering 1,375 hp (1,025 kW) in a highly tuned Lion for 100 miles per hour (160 km/h) in 1933) and even land speed: Lions powered many of Sir Malcolm Campbell's record breakers (including over 250 mph (400 km/h) in 1932) and John Cobb
John Cobb (motorist)
John Rhodes Cobb was a British racing motorist. He made money as a director of fur brokers Anning, Chadwick and Kiver and could afford to specialise in large capacity motor-racing...
's 394 mph Railton Mobil Special in 1947—a record that came well after the Lion had passed its prime and stood until the 1960s. The record had been held by British drivers for 32 years. Lions powered successful entrants in the most prestigious event in air racing, the Schneider Cup, in 1922 and 1927, but were then dropped by Supermarine
Supermarine
Supermarine was a British aircraft manufacturer that became famous for producing a range of sea planes and the Supermarine Spitfire fighter. The name now belongs to an English motorboat manufacturer.-History:...
in favour of a new engine from Rolls-Royce
Rolls-Royce Limited
Rolls-Royce Limited was a renowned British car and, from 1914 on, aero-engine manufacturing company founded by Charles Stewart Rolls and Henry Royce on 15 March 1906 as the result of a partnership formed in 1904....
, the Rolls-Royce R
Rolls-Royce R
The Rolls-Royce R was a British aero engine designed and built specifically for air racing purposes by Rolls-Royce Limited. Nineteen R engines were assembled in a limited production run between 1929 and 1931...
which had been especially designed for racing.
During the 1930s a new generation of much larger and more powerful engines started to appear, and the Lion was clearly past its prime. Gradually, they fell further and further behind. By the time the Bristol Hercules
Bristol Hercules
|-See also:-Bibliography:*Gunston, B. Classic World War II Aircraft Cutaways. Osprey. ISBN 1-85532-526-8*Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9...
and the Rolls-Royce
Rolls-Royce Limited
Rolls-Royce Limited was a renowned British car and, from 1914 on, aero-engine manufacturing company founded by Charles Stewart Rolls and Henry Royce on 15 March 1906 as the result of a partnership formed in 1904....
Merlin
Rolls-Royce Merlin
The Rolls-Royce Merlin is a British liquid-cooled, V-12, piston aero engine, of 27-litre capacity. Rolls-Royce Limited designed and built the engine which was initially known as the PV-12: the PV-12 became known as the Merlin following the company convention of naming its piston aero engines after...
arrived in the late 1930s, the Lion was too small and old-fashioned.
A marine version of the Lion, unsurprisingly called the Sea Lion, was used to power high speed air-sea rescue launches operated by the RAF.
Another adaptation for the Lion aero engine was propeller-driven motor sleighs, which were used for high-speed transport and SAR duties on sea ice by the Finnish Air Force
Finnish Air Force
The Finnish Air Force is one of the branches of the Finnish Defence Forces. Its peacetime tasks are airspace surveillance, identification flights, and production of readiness formations for wartime conditions...
and Navy.
Turning away from the broad arrow layout, Napier started on the design of two new engines using the even more compact H engine
H engine
An H engine is an engine configuration in which the cylinders are aligned so that if viewed from the front, they appear to be in a vertical or horizontal letter H....
layout. The 16-cylinder Rapier
Napier Rapier
|-See also:-Bibliography:* Lumsden, Alec. British Piston Engines and their Aircraft. Marlborough, Wiltshire: Airlife Publishing, 2003. ISBN 1-85310-294-6....
produced 400 hp (300 kW), the 24-cylinder Dagger
Napier Dagger
|-See also:-Bibliography:* Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9...
delivered just under 1,000 hp (750 kW). However these were both smaller than contemporary designs from other companies, and Napier had to start afresh with a new sleeve valve
Sleeve valve
The sleeve valve is a type of valve mechanism for piston engines, distinct from the usual poppet valve. Sleeve-valve engines saw use in a number of pre-World War II luxury cars and in USA in the Willys-Knight car and light truck...
design, which eventually matured into the superb Sabre
Napier Sabre
The Napier Sabre was a British H-24-cylinder, liquid cooled, sleeve valve, piston aero engine, designed by Major Frank Halford and built by Napier & Son during WWII...
.
Variants
| Model | Date | Works No. | Power | Notes | Notable uses |
|---|---|---|---|---|---|
| I | 1918 | 450 bhp at 1,950 rpm | geared, also related IA and 1AY | ||
| II | 1919 | E64 | 450 bhp at 2,000 rpm | ||
| IIII | experimental geared | Gloster Gorcock | |||
| V | 470 hp at 2,000 rpm 500 hp at 2,250 rpm |
VA had increased CR to 5.8 | Mainstay engine of the RAF in the late 1920s, replaced by Lion XI | ||
| VS | E79 | Turbocharged, intercooled | |||
| VIS | 1927 | Turbocharged | Gloster Guan Gloster Guan The Gloster Guan was a single-engined single-seat experimental biplane fighter built in the United Kingdom to test the performance of fighters using supercharged engines at high altitudes. Three were planned but only two constructed.-Development:... |
||
| VII | 1925 | 700 bhp (racing) | Gloster III Gloster III |-See also:-Notes:In addition, the Air Ministry also placed an order with Supermarine for the S.4 monoplane.-Bibliography:*"". Flight. 24 September 1925. pp.609-614.* "". Flight. 29 October 1925. p.703.* "". Flight. 5 November 1925. pp.726-732.... (Schneider Trophy entrant) Supermarine S.4 Supermarine S.4 |-See also:-References:NotesBibliography* Aldgate, Anthony and Jeffrey Richards. Britain Can Take it: British Cinema in the Second World War. Edinburgh: Edinburgh University Press, 2nd Edition. 1994. ISBN 0-7486-0508-8.... |
||
| VIIA | 1927 | E86 | 900 bhp (racing) | Golden Arrow Golden Arrow (land speed racer) Golden Arrow was a land speed record racer. Built for Major Henry Segrave to take the LSR from Ray Keech, Golden Arrow was one of the first streamlined land speed racers, with a pointed nose and tight cowling... Blue Bird (1927) Miss England I Miss England I Miss England I was the name of the first of a series of speedboats used by Henry Segrave and Kaye Don to contest world water speed records in the 1920s and 1930s.- Design and construction :... Supermarine S.5 Supermarine S.5 |-See also:-References:NotesBibliography* Andrews, C.F. and E.B. Morgan. Supermarine Aircraft since 1914, 2nd edition. London: Putnam, 1987. ISBN 0-85177-800-3.... Gloster IV Gloster IV |-References:*"". Flight, 6 October 1927. pp. 695—699.*"The “Gloster IV”". Flight, 1 March 1928. pp. 129—134.*James, Derek J. Gloster Aircraft since 1917. London:Putnam, 1971. ISBN 0 370 00084 6.... |
|
| VIIB | 1927 | 875 bhp (racing) | geared | Supermarine S.5 Supermarine S.5 |-See also:-References:NotesBibliography* Andrews, C.F. and E.B. Morgan. Supermarine Aircraft since 1914, 2nd edition. London: Putnam, 1987. ISBN 0-85177-800-3.... Gloster IV Gloster IV |-References:*"". Flight, 6 October 1927. pp. 695—699.*"The “Gloster IV”". Flight, 1 March 1928. pp. 129—134.*James, Derek J. Gloster Aircraft since 1917. London:Putnam, 1971. ISBN 0 370 00084 6.... |
|
| VIID | 1929 | E91 | 1,350 bhp at 3,600 rpm (racing) | Supercharged, about 6-8 built | Blue Bird (1931) Fred H Stewarts Enterprise Betty Carstairs Betty Carstairs Betty Carstairs was a wealthy British power boat racer known for her speed and her eccentric lifestyle.-Biography:She was born in 1900 as Marion Barbara Carstairs in Mayfair, London, England, the daughter of Frances Evelyn Bostwick, second child of Jabez Bostwick and his wife Helen, and Captain... s Estelle V powerboat Miss Britain III Miss Britain III Miss Britain III is a racing power boat designed and built by Hubert Scott-Paine, a British aircraft and boat designer.During 1932 Hubert Scott-Paine, owner of the British Power Boat Company and already a noted power boat racer, asked Rolls-Royce for a Rolls-Royce 'R' engine which had powered the... Gloster VI Gloster VI -External links:* Royal Air Force.... (Schneider Trophy entrant) Railton Special (John Cobb's land speed record car) |
| VIII | 1927 | direct drive | Gloster Gorcock | ||
| XIA | 1928 | 580 bhp at 2,585 rpm, 6:1 CR | RAF production model | Napier-Railton | |
| Lioness | E71 | Inverted layout, for better visibility. At least some were built turbocharged, for racing. | |||
| Sea Lion | 1933 | 500/600 bhp | Marine version of Lion XI | British Power Boat Company Type Two 63 ft HSL British Power Boat Company Type Two 63 ft HSL The 63 foot long Type 2 High Speed Launch, known as the Whaleback from the distinctive curve to its deck, was a high speed launch class ship used in air-sea rescue to save Allied aircrew from the sea after they were shot down during the Second World War.... |
Aircraft
- Alliance P.2 Seabird
- Avro BisonAvro Bison-See also:...
- Blackburn BlackburnBlackburn Blackburn|-See also:...
- Blackburn DartBlackburn Dart-See also:-Bibliography:* Jackson, A.J. Blackburn Aircraft since 1909. London:Putnam, 1968. ISBN 0-370-00053-6.* Mason, Francis K. The British Bomber since 1914. London:Putnam, 1994. ISBN 0-85177-861-5....
- Blackburn PelletBlackburn Pellet|-See also:...
- Blackburn RiponBlackburn Ripon-See also:-External links:* in Flight...
- Blackburn VelosBlackburn Velos|-See also:-References:* The Illustrated Encyclopedia of Aircraft . London: Orbis Publishing.* Jackson, A.J. Blackburn Aircraft since 1909. London:Putnam, 1968. ISBN 370 00053 6....
- Boulton Paul AtlanticBoulton Paul AtlanticThe Boulton & Paul P.8 Atlantic was Boulton & Paul's attempt to adapt their well-performing Bourges bomber into an airliner. They hoped to gain publicity for it by winning the outstanding prize for the first non-stop Atlantic crossing but a first flight accident made them miss their opportunity...
- Boulton Paul BodminBoulton Paul Bodmin|-See also:-References:NotesBibliography...
- Boulton Paul Bolton
- English Electric KingstonEnglish Electric Kingston|-See also:...
flying boat (prototype) - Fairey IIIFairey IIIThe Fairey Aviation Company Fairey III was a family of British reconnaissance biplanes that enjoyed a very long production and service history in both landplane and seaplane variants...
- Fairey FawnFairey Fawn|-See also:...
- Gloster Gorcock
- Gloster GuanGloster GuanThe Gloster Guan was a single-engined single-seat experimental biplane fighter built in the United Kingdom to test the performance of fighters using supercharged engines at high altitudes. Three were planned but only two constructed.-Development:...
- Handley Page H.P.31 HarrowHandley Page H.P.31 HarrowThe Handley Page H.P.31 was a two-seat single-engined biplane built to a British specification for a carrier based torpedo bomber and reconnaissance aircraft...
- Handley Page HyderabadHandley Page Hyderabad|-See also:-Bibliography:* Barnes, C. H. Handley Page Aircraft Since 1907. London: Putnam & Company, Ltd., 1987. ISBN 0-85177-803-8.* Clayton, Donald C. Handley Page, an Aircraft Album. Shepperton, Surrey, UK: Ian Allan Ltd., 1969. ISBN 0-7110-0094-8....
- Mitsubishi B1MMitsubishi B1M-See also:-External links:**http://www.csd.uwo.ca/~pettypi/elevon/gustin_military/db/index.html...
- Parnall Pike
- Parnall PossumParnall PossumThe Parnall Possum was an experimental triplane, with a single, central engine driving wing mounted propellers via shafts and gears. Two of these British aircraft were built in the mid-1920s.-Design and development:...
- Parnall PuffinParnall Puffin-External links:* side photo* FLIGHT November 1921, more detailed photos...
- Supermarine S.4Supermarine S.4|-See also:-References:NotesBibliography* Aldgate, Anthony and Jeffrey Richards. Britain Can Take it: British Cinema in the Second World War. Edinburgh: Edinburgh University Press, 2nd Edition. 1994. ISBN 0-7486-0508-8....
- Supermarine S.5Supermarine S.5|-See also:-References:NotesBibliography* Andrews, C.F. and E.B. Morgan. Supermarine Aircraft since 1914, 2nd edition. London: Putnam, 1987. ISBN 0-85177-800-3....
- Supermarine SeagullSupermarine Seagull (1921)|-Specifications :-See also:-Bibliography:* Andrews, C.F. and Morgan, E.B. Supermarine Aircraft Since 1914. London: Putnam Books Ltd., 2nd revised edition 2003. ISBN 0-851-77800-3....
- Supermarine SouthamptonSupermarine Southampton-See also:-References:NotesBibliography* Andrews, C.F. and E.B. Morgan. Supermarine Aircraft since 1914 . London: Putnam, 1987. ISBN 0-85177-800-3....
- Tarrant TaborTarrant Tabor- See also :* Witteman-Lewis XNBL-1 - a design by Barling for a similar aircraft for the US Army- External links :* http://avia.russian.ee/air/england/tarrant_tabor.php* http://members.aol.com/wwatrans/unique.htm...
- Vickers VernonVickers Vernon-See also:...
- Vickers ValparaisoVickers Valparaiso|-See also:-External links:*...
- Vickers VictoriaVickers Victoria-See also:...
- Vickers VirginiaVickers Virginia|-See also:-References:NotesBibliography* Andrews, C.F. and E.B. Morgan. Vickers Aircraft since 1908. London: Putnam, 1989. ISBN 0-85177-851-1....
- Vickers VixenVickers Vixen|-See also:-External links:*...
- Westland WalrusWestland Walrus|-References:...
Other applications
- British Power Boat Company Type Two 63 ft HSLBritish Power Boat Company Type Two 63 ft HSLThe 63 foot long Type 2 High Speed Launch, known as the Whaleback from the distinctive curve to its deck, was a high speed launch class ship used in air-sea rescue to save Allied aircrew from the sea after they were shot down during the Second World War....
- British Power Boat Company 60 ft 4 in
Engines on display
Preserved Napier Lion engines are on static display at the following museums:- Brooklands MuseumBrooklands MuseumBrooklands Museum is an independent charitable trust, established in 1987, whose aim is to conserve, protect and interpret the unique heritage of the Brooklands site. It is located south of Weybridge, Surrey and was first opened regularly in 1991 on of the original 1907 motor-racing circuit...
- Canada Aviation MuseumCanada Aviation MuseumThe Canada Aviation and Space Museum is Canada's national aviation history museum. The museum is located in Ottawa, Ontario, Canada, at the Ottawa/Rockcliffe Airport...
- Imperial War Museum DuxfordImperial War Museum DuxfordImperial War Museum Duxford is a branch of the Imperial War Museum near the village of Duxford in Cambridgeshire, England. Britain's largest aviation museum, Duxford houses the museum's large exhibits, including nearly 200 aircraft, military vehicles, artillery and minor naval vessels in seven...
- Solent SkySolent SkySolent Sky is an aviation museum in Southampton, Hampshire, previously known as Southampton Hall of Aviation.It depicts the history of aviation in Southampton, the Solent area and Hampshire. There is special focus on the Supermarine aircraft company, based in Southampton, and its most famous...