The Hispano-Suiza 12N was one of two new V-12 engine designs first run in 1928 and was manufactured by

Hispano-Suiza Hispano-Suiza () is a Spanish automotive company. It was founded in 1904 by Marc Birkigt and as an automobile manufacturer and eventually had several factories in Spain and France that produced luxury cars, aircraft engines, trucks and weapons. ...

's French

subsidiary A subsidiary, subsidiary company, or daughter company is a company (law), company completely or partially owned or controlled by another company, called the parent company or holding company, which has legal and financial control over the subsidia ...

for the Armée de l’Air. It produced about , was the first to use gas nitride hardening and introduced wet cylinder liners into Hispano-Suiza's aircraft engine range. It powered the first non-stop flight from

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

to the United States.

Design and development

Up to 1927, Hispano-Suiza's many engine types, of various layouts and cylinder numbers, were all recognisable developments of the

World War I World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a World war, global conflict between two coalitions: the Allies of World War I, Allies (or Entente) and the Central Powers. Fighting to ...

V-8

Hispano-Suiza 8 The Hispano-Suiza 8 is a Internal combustion engine cooling, water-cooled V8 engine, V8 SOHC aero engine introduced by Hispano-Suiza in 1914 that went on to become the most commonly used liquid-cooled engine in the aircraft of the Entente Powers ...

. 1927-8 saw the introduction of four completely new engines, two V-12s and two with six cylinders inline. The Hispano-Suiza 12N, known by the manufacturers as the Type 61, was the larger of the V-12s, with a

displacement Displacement may refer to: Physical sciences Mathematics and physics *Displacement (geometry), is the difference between the final and initial position of a point trajectory (for instance, the center of mass of a moving object). The actual path ...

of , the other being the 12M. Apart from capacity and power, these two engines had much in common. The 12M first ran in 1927 and the 12N a year later. Both 12M and 12N were 60° V engines with

carburettor A carburetor (also spelled carburettor or carburetter) is a device used by a gasoline internal combustion engine to control and mix air and fuel entering the engine. The primary method of adding fuel to the intake air is through the Vent ...

inlets An inlet is a typically long and narrow indentation of a shoreline such as a small arm, cove, bay, sound, fjord, lagoon or marsh, that leads to an enclosed larger body of water such as a lake, estuary, gulf or marginal sea. Overview In marin ...

and exhausts on the outer faces. There were three carburettors per bank, each charging a pair of

cylinders A cylinder () has traditionally been a three-dimensional solid, one of the most basic of curvilinear geometric shapes. In elementary geometry, it is considered a prism with a circle as its base. A cylinder may also be defined as an infinite ...

. Much of the new technology was in the cylinder design: these types introduced

wet liner In an engine, the cylinder is the space in which a piston travels. The inner surface of the cylinder is formed from either a thin metallic liner (also called "sleeve") or a surface coating applied to the engine block. A piston is seated inside e ...

s, an Hispano automobile engine innovation which brought the cooling water into direct contact with the steel cylinder barrel rather than through a screwed-in aluminium water jacket. This improved cooling, simplified assembly and allowed larger cylinder bores without increasing their separation. The cylinder barrels were open at top and bottom and threaded for screwing into the block only near the top, with valve seats ground into the aluminium cylinder head. The lower end of the barrel extended into the crankcase, simplifying both manufacture and assembly. Block and crankcase were bolted together. The 12M and 12N engines were the first to use the gas nitriding surface-hardening process on the cylinder walls, which reduced both wear and oil consumption. They also used a novel, complicated but effective method of

main bearing A main bearing is a bearing in a piston engine which holds the crankshaft in place and allows it to rotate within the engine block. The number of main bearings per engine varies between engines, often in accordance with the forces produced b ...

cooling, enhancing the local lubricant flow without requiring high overall oil pump speeds. Both types were designed so that

epicyclic gearing An epicyclic gear train (also known as a planetary gearset) is a gear reduction assembly consisting of two gears mounted so that the center of one gear (the "planet") revolves around the center of the other (the "sun"). A carrier connects the ...

could be added or removed quickly; some earlier Hispano-Suiza engines offered gearing but as a permanent fixture on a specific sub-type. The gears added to the weight. In 1935 the 12Ner variant was fitted with an in-flight electrically operated variable pitch propeller. The 12N series was developed into the 12Y (Type 73)

supercharged In an internal combustion engine, a supercharger compresses the intake gas, forcing more air into the engine in order to produce more power for a given displacement. It is a form of forced induction that is mechanically powered (usually by ...

engine, first run in 1932.

Operational history

A Hispano-Suiza 12Nb powered the Breguet XIX ''Point d'Interrogation'' on the first non-stop flight from

Paris Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, largest city of France. With an estimated population of 2,048,472 residents in January 2025 in an area of more than , Paris is the List of ci ...

to New York in September 1930. This was the first east to west flight between

and the United States, rather than to the North American continent. In the early 1930s, 12N engines powered the

flying boat A flying boat is a type of seaplane with a hull, allowing it to land on water. It differs from a floatplane in having a fuselage that is purpose-designed for flotation, while floatplanes rely on fuselage-mounted floats for buoyancy. Though ...

s operating the French Atlantic and

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n routes. The

Swiss Swiss most commonly refers to: * the adjectival form of Switzerland * Swiss people Swiss may also refer to: Places * Swiss, Missouri * Swiss, North Carolina * Swiss, West Virginia * Swiss, Wisconsin Other uses * Swiss Café, an old café located ...

government, in the form of the KTA (Kriegstechninischen Abteilung or War Technical Department) purchased construction licences for the 12Nb and in 1932 eighty units were built at the

Saurer Adolph Saurer AG was a Swiss manufacturer of embroidery and textile machines, trucks and buses under the Saurer and Berna (beginning in 1929) brand names. Based in Arbon, Switzerland, the firm was active between 1903 and 1982. Their vehicles were ...

lorry factory.

Variants

''Data from Hispano Suiza in Aeronautics.'' ;12Nb/650: Compression ratio 6.2, maximum power at 2,100 rpm. ;12Nbr/650: Compression ratio 6.2, maximum power at 2,100 rpm. Gearing ratio of 2:1 or 1.61:1. ;12Ns: Compression ratio 7, nominal power at 2,200 rpm. For

Schneider Cup The Coupe d'Aviation Maritime Jacques Schneider, also known as the Schneider Trophy, Schneider Prize or (incorrectly) the Schneider Cup is a trophy that was awarded first annually, and later biennially, to the winner of a race for seaplanes and f ...

1928. ;12Nsr: Compression ratio 10, nominal power at 2,400 rpm. For Schneider Cup 1931.

Farman Farman Aviation Works () was a French aircraft company founded and run by the brothers Richard, Henri, and Maurice Farman. They designed and constructed aircraft and engines from 1908 until 1936; during the French nationalization and rational ...

compressor. ;12Nc: Compression ratio 6.2, nominal power at 2,000 rpm. For Ford 14A Trimotor. ;12Ncr: ;12Ndr: Electrically controlled pitch propeller, anti-clockwise turning (1935). ;12Ner: As 12Ndr, modified with articulated

connecting rod A connecting rod, also called a 'con rod', is the part of a reciprocating engine, piston engine which connects the piston to the crankshaft. Together with the crank (mechanism), crank, the connecting rod converts the reciprocating motion of the p ...

s. ;12Nfr: As Ndr, clockwise turning. ;12Ngr: As Ner, clockwise turning.

Applications

Specifications (12Nbr/650)

References