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 Air racing is a type of motorsport that involves airplanes or other types of aircraft that compete over a fixed course, with the winner either returning the shortest time, the one to complete it with the most points, or to come closest to a previ ...

, built in France during the latter half of the 1920s.

Design and development

After failing to enter the Schneider Trophy seaplane race for several years, the French Ministère de l’Air decided to enter the 1929 competition. Two companies were tasked with designing and building floatplane racers to compete with the entries from Italy and Great Britain, resulting in the

Nieuport-Delage NiD-450 Nieuport, later Nieuport-Delage, was a French aeroplane company that primarily built racing aircraft before World War I and fighter aircraft during World War I and between the wars. History Beginnings Originally formed as Nieuport-Duplex in ...

and

Bernard H.V.120 The Bernard H.V.120 was a racing seaplane designed and built by the French aircraft manufacturer Bernard. It was developed specifically to compete in the Schneider Trophy race. The company developed it as a wooden single-seat mid-wing canti ...

, both of which were powered by the specially designed Hispano-Suiza 18R engines. To power the racers Hispano-Suiza married three six cylinder blocks from the

Hispano-Suiza 12Nb The Hispano-Suiza 12N was one of two new V-12 engine designs first run in 1928 and was manufactured by Hispano-Suiza's French subsidiary for the Armee d'l'Air. It produced about , was the first to use nitriding, gas nitride hardening and introdu ...

to a common crankshaft / crankcase, set at 80° to each other. Retaining the bore and stroke of the 12Nb, the 18R had the compression ratio increased from 6.25:1 to 10:1 with a total displacement of 54.075L (3,299.8ci). Each cylinder aspirated through two valves operated by single overhead cam-shafts with ignition from two spark plugs set on opposite sides of the combustion chamber supplied by magnetos at the rear of the engine. Fuel metering was carried out by nine carburetors each supplying two cylinders. Construction of the 18R was largely of Elektron magnesium alloy for body components with high strength steels for highly loaded parts such as the crankshaft. In common with many multiple bank and radial engines the pistons were connected to the crankshaft via master and slave connecting rods; the central vertical bank was served by the master rod which housed the big-end bearing with connecting rods articulating from this to the other two banks. The 18R was available with or without a Farman (bevel planetary) reduction gear. Development issues delayed production of the engine, with the first geared drive engine delivered to Nieuport-Delage in October 1929, a month after the 1929 Schneider Trophy race. Despite the effort put into its development the 18R proved to be unreliable and unable to achieve the expected power output. The poor performance of the 18R prompted the development of the 18S, a de-rated version intended for commercial use. Reducing the compression ratio to 6.2:1 at a maximum rpm of 2,000 and replacing the Elektron with aluminium alloy, the 18S was available with or without the Farman reduction gear, but was not a success, only powering the

Ford 14A The Ford Trimotor (also called the "Tri-Motor", and nicknamed the "Tin Goose") is an American three-engined transport aircraft. Production started in 1925 by the companies of Henry Ford and ended on June 7, 1933, after 199 had been made. It ...

in the pylon mounted central nacelle.

Operational history

The 18R and 18S did not have successful careers, only powering four aircraft types in very small production numbers, proving to be totally outclassed by contemporary racing engines, such as the Rolls-Royce R which powered the

Supermarine S.6 The Supermarine S.6 is a 1920s British single-engined single-seat racing seaplane built by Supermarine. The S.6 continued the line of Supermarine seaplane racers that were designed for Schneider Trophy contests of the late 1920 and 1930s. Desi ...

family of floatplane racers.

Variants

''Data from:'' ;18R: The original racing engine with 10:1 compression ratio, available with or without the Farman reduction gearing. ;18Sb: The de-rated. 6.2:1 compression ratio, commercial version without the Farman reduction gearing. ;18Sbr: The 18Sb with the Farman reduction gearing.

Applications

''Data from:'' *

Nieuport-Delage NiD 450 The Nieuport-Delage NiD 450 was a French racing floatplane, originally intended to compete for the 1929 Schneider Trophy. After the French decided not to participate that year, the type was used as the NiD 650 to speed the development of the pro ...

* Nieuport-Delage NiD 650 (converted from the 2 NiD 450 aircraft) *

* Bernard V-4 (landplane conversion of the H.V.120-01) *

Engines on display

One Hispano-Suiza 18Sbr engine is preserved at the Musée de l’Air et de l’Espace (Air & Space Museum), Le Bourget, France.''Data from:''

Design and development

Operational history

Variants

Applications

Engines on display

Specifications (18R)

See also

References

Further reading