Bugatti U-16

U-16
	The King-Bugatti U-16
Type	Piston aircraft engine
Manufacturer	Bugatti / Duesenberg Motor Corporation
First run	1916

Last updated April 05, 2024

The Bugatti U-16 was a 16-cylinder water-cooled double-8 vertical in-line "U engine", designed by Ettore Bugatti in 1915 to 1916 and built in France in small numbers. The US Bolling Commission bought a license to build the engine in the US,^[1] and small numbers of a slightly revised version were built by the Duesenberg Motor Corporation as the King-Bugatti. Probably about 40 King-Bugattis were made before the end of World War I caused building contracts to be canceled.^[2]

Design and development

The U-16 engine was designed to use as many features of a previous Bugatti 8-cylinder in-line "straight-eight" engine as possible. Two eight-cylinder banks were mounted vertically side by side on a common cast aluminium crankcase, each bank driving its own crankshaft. The two crankshafts were geared to and drove a single common airscrew shaft. The shaft was bored to accept a 37-mm gun barrel, and a clear passage was provided through the crankcase in line with the shaft boring for the same purpose.^[3] Each eight-cylinder bank was made up of two cast iron four-cylinder blocks; the crankshafts were each made up of two standard four-cylinder crankshafts joined end to end by a fine taper cone joint. To reduce overall length, these crankshafts were undercut:^[4] a typical Bugatti approach, where only their unlimited budget and attention to detail could afford such complexities.

A bevel gear at the junction drove a vertical shaft from which the single overhead camshaft and dual magnetos for each bank were driven. Two magnetos were mounted on the outside of each cylinder bank. Each magneto fired all eight cylinders for that bank, driven by bevel gear from the vertical shaft that also drove the bank's single overhead camshaft. Each cylinder had two vertical inlet valves and a single vertical exhaust valve, all driven by rocking levers from the camshaft. Four carburettors each fed four cylinders via a water jacketed manifold. Each cylinder exhausted into an individual pipe in the space between the cylinder blocks.^[3] The whole construction was protected by patents until 1935.^[5]

The engine completed ten-hour and fifty-hour endurance tests in 1917, and the French government purchased a license and arranged for production by Peugeot. During the fifty-hour test a US sergeant who was observing the test for the Bolling Commission was killed by the propeller, becoming the first US serviceman to die on active service during World War I.^[5]

The Bolling Commission and the "Bugatti Mission"

In 1917 a US military mission headed by Colonel R.C. Bolling visited Europe to choose aero engines to be produced for the Aviation Section, Signal Corps. The mission was accompanied by a group of civilian experts headed by the engine manufacturer Howard Marmon. The Bugatti U-16 aroused interest and Marmon arranged for a license to be purchased for $100,000 by the US government.^[1]^[5] In December 1917 a "Bugatti Mission" sailed from Bordeaux for the US to supervise production of the engine at the Duesenberg Motor Corporation of Elizabeth, New Jersey, where the engines were planned to be made.^[5]

US revisions

The US government engaged Colonel Charles Brady King, to redesign the engine for production in the US, much to Ettore Bugatti's irritation.^[6] Col. King was then an aeronautical mechanical engineer for the Signal Corps, and head of its division of engine design.

A prototype engine was sent to McCook Field near Dayton, Ohio after only 37 hours of testing. It was then decided to send it with Colonel King to Duesenberg for further development. In February, 1918, this engine blew apart due to structural weakness.^[7] King improved some of the design details of the engine, such as the lack of water cooling around the valve seats and the close pitch of valves. Accordingly, King's revisions to the design altered the cylinder heads to provide freer water circulation, better valve cooling, and a slight increase in the distance between valve centres.^[3]

Post World War I developments

Neither Bugatti's U-16 or the King-Bugatti were particularly successful engines. Few were installed in aircraft, and even fewer actually flew. After World War I no further developments were made in the US, while in France Breguet took over the license and continued development under the designation "Type U-24". In 1920 Breguet showed a "quadrimoteur" made of two Type U-16s coupled together, with provision to de-clutch any cylinder bank to enable it to be stopped while the other three units continued to provide power.^[4]

Variants

Bugatti U-16: (1915)
King-Bugatti: (1918)

Breguet

Breguet-Bugatti U.16: The licence built U.16, essentially similar to the King-Bugatti but with reduced bore to improve reliability
Breguet-Bugatti U.24: An increased displacement U-16 engine
Breguet-Bugatti U.24bis
Breguet-Bugatti 32A Quadrimotor Type A: Two U.24s mounted in tandem, nose to nose with a combining gearbox between the engine halves, driving the propeller through an extension shaft passing through the cylinder banks of the forward engine half.^[8]
Breguet-Bugatti 32B Quadrimotor Type B: A development of the quadrimotor concept with four U-16 8-cylinder blocks mounted in an 'H' configuration, driving a single propeller via a combining gearbox though centrifugal clutches.^[8]

Breguet-Bugatti H-32B: Alternative designation for the type 32B Quadrimoteur.

Applications

Bugatti U-16: Morane-Saulnier AN, 1918 prototype fighter aircraft
King-Bugatti: Packard-Le Père LUSAC-21 ^[5]
Breguet-Bugatti: Breguet XIX, 1921 (but not flown with this engine); Breguet 20 "Leviathan", 1920.; Breguet 21 "Leviathan", 1921.; Breguet 22.^[9]

Engines on display

A King Bugatti on display King-Bugatti-U16.JPG — A King Bugatti on display

The Musee de l'air at Chalais-Meudon, 2 rue des Vertugadins, Meudon (just outside the Paris boundaries in the south west direction) holds a French U-16 engine and two Breguet-Bugatti engines. A King-Bugatti can be seen at the National Air Museum of the Smithsonian Institution in Washington, D.C., and another in the USAF museum at the Wright-Patterson AF Base at Fairborn, Ohio.^[10] The Auburn-Cord-Duesenberg Museum in Auburn, Indiana also has a King-Bugatti engine on display in their Hall of Technology ^[11]

Specifications (King-Bugatti)

Data from Jane's fighting aircraft of World War I,^[3] Jane's All the World's Aircraft 1919^[12] except where indicated. Later specifications quote slightly varied detail dimensions and increased horsepower ratings.

General characteristics

Type: 16-cylinder water-cooled double vertical in-line engine
Bore: 4.33 in (110 mm)
Stroke: 6.3 in (160 mm)
Displacement: 1,484.3 cu in (24.3 L)
Length: about 44.25 in (1,124 mm)^[13]
Width: about 24.8 in (630 mm)^[13]
Height: about 32.28 in (820 mm)^[13]
Dry weight: 1,286 lb (583.3 kg)^[13]

Components

Valvetrain: Split overhead camshaft per cylinder bank operating 3 valves per cylinder (2 inlet, one exhaust), driven by a shaft and bevel gers from the centre of the crankshaft.
Fuel system: 4 carburettors, one for each bank of four cylinders
Fuel type: Petrol
Oil system: Dry sump, one scavenging pump and one pressure pump each driven from the front ends of the camshafts
Cooling system: Water-cooled
Reduction gear: 0.6666
4x Dixie 800 magnetos

Performance

Power output: 410 hp (306 kW) at 2,000 rpm
Compression ratio: 5:1
Power-to-weight ratio: 0.42 hp/lb (0.7 kW/kg)

Related Research Articles

The straight-eight engine or inline-eight engine is an eight-cylinder internal combustion engine with all eight cylinders mounted in a straight line along the crankcase. The type has been produced in side-valve, IOE, overhead-valve, sleeve-valve, and overhead-cam configurations.

<span class="mw-page-title-main">U engine</span>

A U engine is a piston engine made up of two separate straight engines placed side-by-side and coupled to a shared output shaft. When viewed from the front, the engine block resembles the letter "U".

An overhead camshaft (OHC) engine is a piston engine in which the camshaft is located in the cylinder head above the combustion chamber. This contrasts with earlier overhead valve engines (OHV), where the camshaft is located below the combustion chamber in the engine block.

The Renault 8G was a family of French liquid-cooled V-8 aero engines of the World War I era that produced from 140 hp (100 kW) to 190 hp (140 kW).

The Green D.4 was a four-cylinder watercooled inline piston engine produced by the Green Engine Co in the UK in 1909. It produced about 60 hp (45 kW) and played an important role in the development of British aviation before World War I.

E.N.V. was an early manufacturer of aircraft engines, originally called the London and Parisian Motor Company, their first model appearing in 1908. E.N.V. engines were used by several pioneer aircraft builders and were produced in both France and the UK until about 1914. They subsequently specialised in camshafts and bevel gear manufacture until 1968 when the name was lost.

The Lorraine 12H Pétrel was a French V-12 supercharged, geared piston aeroengine initially rated at 370 kW (500 hp), but later developed to give 640 kW (860 hp). It powered a variety of mostly French aircraft in the mid-1930s, several on an experimental basis.

The Asso XI was a family of water-cooled, supercharged V12 piston aeroengines produced in the 1930s by Italian manufacturer Isotta Fraschini, and fitted on a number of aircraft types built by CANT, Caproni and others.

The CNA C-7 was a small nine-cylinder supercharged, geared, single row radial engine designed in Italy in the early 1930s. Three light aircraft class world altitude records were set by the CNA C-7 powered Fiat AS.1 and CNA Eta.

The Austin 25-30 is a motor car. It was the first automobile produced by newly established British car manufacturer Austin.

The Fiat AN.1 was an experimental Italian water-cooled diesel straight six cylinder aircraft engine from the late 1920s.

The Hispano-Suiza 18R was an eighteen cylinder high performance water-cooled piston engine, in an 80° W or broad arrow layout, for use in racing aircraft, built in France during the latter half of the 1920s.

The Renault 100 hp, or 12B, aircraft engine from 1912 was a twelve-cylinder, air cooled 60° vee engine built by the French Renault company.

<span class="mw-page-title-main">Renault 130 hp V-12</span> 1910s French piston aircraft engine

The Renault 130 hp V-12 aircraft engine is a twelve-cylinder, air cooled 90° vee engine built by the French Renault company.

The De Dion-Bouton 78 hp, typically referred to as De Dion-Bouton 80 hp, was an eight-cylinder, air cooled vee aircraft engine that has been built by De Dion-Bouton.

The De Dion-Bouton 130 hp aircraft engine, also referred to as De Dion-Bouton 12B, was a twelve-cylinder, air cooled vee aircraft engine that has been built by De Dion-Bouton.

The Rapp 100 hp was a four-cylinder, SOHC valvetrain liquid-cooled inline aircraft engine built by Rapp Motorenwerke. The engine originated from Karl Rapp's earlier 90 hp four-cylinder that he had designed at the Flugwerk Deutschland GmbH for the 1912/13 Kaiserpreis aircraft engine contest.

The Rapp 125/145 hp, also referred to as Rapp Rp II, was a water-cooled 90° V-8 aircraft engine built by Rapp Motorenwerke in 1915.

The Rapp 200 hp was a water-cooled 90° V-8 aircraft engine built by Rapp Motorenwerke.

The Renault 50/60 hp aircraft engines were a series of air cooled 90° V-8 engines with a bore and stroke of 90 mm × 120 mm built by the French Renault company in the years from 1908 to about 1911.

References

1 2 "Bugatti Model 100 Racer". Archived from the original on 2011-12-21. Retrieved 2009-08-29.
↑ "The Bugatti revue: Bugatti License Aircraft Engines". Archived from the original on 2020-01-19. Retrieved 2009-08-29.
1 2 3 4 John W.R. Taylor (1990). "Forward". In Whittaker, W. E. De. B. (ed.). Jane's Fighting Aircraft of World War I. New York, N.Y.: Military Press. pp. 275–277. ISBN 978-0517033760.
1 2 Jaap Horst, ed. (1 August 1996). "Bugatti Licensed Aircraft Engines". The Bugatti Revue. 1 (3).
1 2 3 4 5 L'Ebé Bugatti, 1966, "The Bugatti Story", Editions de la Table Ronde & L'Action Automobile, first British edition 1967, Len Ortzen (translator) and Souvenir Press Ltd, London, pps 70-72, p162
↑ The Design Council, London, 1979, "The Amazing Bugattis", Heinemann Educational Books, ISBN 0-85072-104-0, p 66
↑ William Pearce: Duesenberg Aircraft Engines: A Technical Description. Old Machine Press 2012; p 44
1 2 "Bréguet-Bugatti 32A and 32B Quadimoteurs". Old Machine Press. 17 January 2015. Retrieved 10 March 2018.
↑ Horst, Jaap. "the Bugatti revue: Bugatti Powered Aircraft". www.bugattirevue.com. Retrieved 20 December 2020.
↑ "Bugatti Aircraft Association - Ettore Bugatti".
↑ "Hall of Technology". Archived from the original on 2011-02-06. Retrieved 2011-02-02.
↑ Grey, C.G., ed. (1969). Jane's All the World's Aircraft 1919 (Facsimile ed.). London: David & Charles Limited. pp. 52b–57b. ISBN 07153-4647-4.
1 2 3 4 "King-Bugatti U-16 Engine". Smithsonian National Air and Space Museum. Retrieved 1 January 2011.

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.

[racer-1] 1 2 "Bugatti Model 100 Racer". Archived from the original on 2011-12-21. Retrieved 2009-08-29.

[bugatti1-2] "The Bugatti revue: Bugatti License Aircraft Engines". Archived from the original on 2020-01-19. Retrieved 2009-08-29.

[Janes-3] 1 2 3 4 John W.R. Taylor (1990). "Forward". In Whittaker, W. E. De. B. (ed.). Jane's Fighting Aircraft of World War I. New York, N.Y.: Military Press. pp. 275–277. ISBN 978-0517033760.

[BR,_3-3-4] 1 2 Jaap Horst, ed. (1 August 1996). "Bugatti Licensed Aircraft Engines". The Bugatti Revue. 1 (3).

[L'Ebe-5] 1 2 3 4 5 L'Ebé Bugatti, 1966, "The Bugatti Story", Editions de la Table Ronde & L'Action Automobile, first British edition 1967, Len Ortzen (translator) and Souvenir Press Ltd, London, pps 70-72, p162

[design-6] The Design Council, London, 1979, "The Amazing Bugattis", Heinemann Educational Books, ISBN 0-85072-104-0, p 66

[Pearce(2012)44-7] William Pearce: Duesenberg Aircraft Engines: A Technical Description. Old Machine Press 2012; p 44

[omp-8] 1 2 "Bréguet-Bugatti 32A and 32B Quadimoteurs". Old Machine Press. 17 January 2015. Retrieved 10 March 2018.

[bugattirev-9] Horst, Jaap. "the Bugatti revue: Bugatti Powered Aircraft". www.bugattirevue.com. Retrieved 20 December 2020.

[10] "Bugatti Aircraft Association - Ettore Bugatti".

[11] "Hall of Technology". Archived from the original on 2011-02-06. Retrieved 2011-02-02.

[JAWA1919-12] Grey, C.G., ed. (1969). Jane's All the World's Aircraft 1919 (Facsimile ed.). London: David & Charles Limited. pp. 52b–57b. ISBN 07153-4647-4.

[NASM-13] 1 2 3 4 "King-Bugatti U-16 Engine". Smithsonian National Air and Space Museum. Retrieved 1 January 2011.

[1]

[2]

[3]

[4]

[5]

[6]

[7]

[8]

[9]

[10]

[11]

[12]

[13]