Hispano-Suiza 18R
| Industry | Aerospace, Automotive |
|---|---|
| Founded | 1904 in France |
| Headquarters | France |
| Products | Aircraft engines, Automobiles |
The Hispano-Suiza 18R was a water-cooled piston engine featuring eighteen cylinders arranged in an 80° W or broad arrow configuration. Designed in France during the late 1920s, it targeted high-performance applications in racing aircraft.
Design and development
To compete in the 1929 Schneider Trophy seaplane contest, the French Ministère de l’Air commissioned two floatplane racers—the Nieuport-Delage NiD-450 and the Bernard H.V.120—both utilizing the Hispano-Suiza 18R powerplant.
The 18R’s architecture consisted of three six-cylinder banks derived from the Hispano-Suiza 12Nb, arranged around a shared crankshaft at an 80° angle. It maintained the original bore of 150 mm and stroke of 170 mm from the 12Nb but increased the compression ratio from 6.25:1 to 10:1, resulting in a total displacement of 54.075 liters (3,299.8 cubic inches). Each cylinder was equipped with two valves actuated by single overhead camshafts and featured dual spark plugs ignited by magnetos. Fuel supply was managed by nine carburetors, each serving a pair of cylinders.
Primarily constructed using lightweight Elektron magnesium alloy, critical components such as the crankshaft were fabricated from high-strength steel. The engine employed master-and-slave connecting rods to connect pistons to the crankshaft, with the central vertical bank’s master rod containing the big-end bearing and articulating to rods on the adjacent banks. The 18R was available in configurations both with and without a Farman bevel planetary reduction gear.
Due to production setbacks, the first geared version of the engine was delivered to Nieuport-Delage only in October 1929—after the Schneider Trophy event had concluded. Despite extensive development efforts, the 18R faced reliability challenges and failed to achieve its targeted power output. Consequently, a de-rated commercial variant designated as the 18S was developed, featuring a reduced compression ratio of 6.2:1 and limiting maximum rpm to 2,000. This version also replaced Elektron with aluminum alloy for construction. Offered with optional reduction gearing, the 18S experienced limited adoption, powering exclusively the central nacelle engine of the Ford 14A trimotor.
Operational history
Both the 18R and its derivative, the 18S, saw restricted operational deployment, being installed on only four aircraft models in small quantities. These engines were eclipsed by contemporary racing powerplants such as the Rolls-Royce R, which propelled the Supermarine S.6 seaplane racers.
Variants
Data sourced from:[1]
- 18R
- Initial racing variant with a compression ratio of 10:1; available with or without Farman planetary reduction gearing.
- 18Sb
- Commercially oriented de-rated model featuring a compression ratio of 6.2:1 and no reduction gear.
- 18Sbr
- Farman geared version of the 18Sb variant.
Applications
Source:[1]
- Nieuport-Delage NiD 450
- Nieuport-Delage NiD 650 (modified from NiD 450)
- Bernard H.V.120
- Bernard V-4 (landplane adaptation of H.V.120-01)
- Ford 14A
Engines on exhibit
An example of the Hispano-Suiza 18Sbr engine is maintained at the Musée de l’Air et de l’Espace, located in Le Bourget, France.Source:[1]
Further reading
- Schneider Trophy Seaplanes and Flying Boats by Ralph Pegram (2012)
- Hispano Suiza in Aeronautics by Manuel Lage (2004)
- Aerosphere 1939 by Glenn Angle (1940)
- Jane's All the World's Aircraft 1931–1933 by C.G. Grey
- Beyond the Model T: The Other Ventures of Henry Ford by Ford Bryan (1997)