Hispano-Suiza 8


The Hispano-Suiza 8 is a water-cooled 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 during the First World War. The original Hispano-Suiza 8A was rated at and the later, larger displacement Hispano-Suiza 8F reached.
Hispano-Suiza 8 engines and variants produced by Hispano-Suiza and other companies under licence were built in twenty-one factories in Spain, France, Britain, Italy, and the U.S. Derivatives of the engine were also used abroad to power numerous aircraft types and the engine can be considered as the ancestor of another successful engine by the same designer, the Hispano-Suiza 12Y which was in service during the Second World War.

Design and development

Origins

At the beginning of World War I, the production lines of the Barcelona based Hispano-Suiza automobile and engine company were switched to the production of war materiel. Chief engineer Marc Birkigt led work on an aircraft engine based on his successful V8 automobile engine. The resulting engine, called the Hispano-Suiza 8A, made its first appearance in February 1915.
The first 8A kept the standard configuration of Birkigt's existing design: eight cylinders in 90° Vee configuration, a displacement of 11.76 litres and a power output of 140 hp at 1,900 rpm. In spite of the similarities with the original design, the engine had been substantially refined. The crankshaft was machined from a solid piece of steel. The cylinder blocks were cast aluminium and of monobloc type that is, in one piece with the SOHC cylinder heads. The inlet and exhaust ports were cast into the blocks, the valve seats were in the top face of the steel cylinder liners, which were screwed into the blocks. Using a rotating bevel gear-driven tower shaft coming up from the crankcase along the rear end of each cylinder bank, with the final drive for each cylinder bank's camshaft accommodated within a semicircular bulge at the rear end of each valve cover. Aluminium parts were coated in vitreous enamel to reduce leakage. All parts subject to wear, and those critical for engine ignition were duplicated: spark plugs for dual ignition reliability, valve springs, magnetos, etc.
The new engine was presented to the French Ministry of War in February 1915, and tested for 15 hours at full power. This was standard procedure for a new engine design to be admitted into military service. However, because of lobbying by French engine manufacturers, the Spanish-made engine was ordered to undergo a bench test that no French-made engine had yet passed: a 50-hour run at full speed. The HS-31 was therefore sent back to Chalais-Meudon on July 21, 1915, and tested for 50 hours, succeeding against all expectations. The design also promised far more development-potential than rotary engines. This was despite being the most common type, then in use, for most aircraft.
French officials ordered production of the 8A to be started as soon as possible and issued a requirement for a new single-seat high-performance fighter aircraft using the new engine. The Louis Béchereau-designed SPAD VII was the result of this requirement and allowed the Allies to regain air superiority over the Germans.

Production history

The Hispano-Suiza 8 was the most produced aero engine series of World War I with 49,893 units manufactured during the conflict. The engine continued to be built in smaller numbers during the 1920s. Most of the engines were built under license in factories located in France, the United Kingdom, the United States and Italy. Small numbers of engines were also built in Japan, Spain, Switzerland and the Soviet Union.

France

In total 35,189 Hispano-Suiza 8 engines were produced in France during World War I. Fourteen French companies produced the engines under license including Ariès, Brasier, Chenard-Walcker, De Dion-Bouton, Peugeot and Voisin. Peugeot were the single largest manufacturer of the 200 hp Hispano Suiza 8 with 5,506 engines built. The Hispano-Suiza 8 shared many common parts with the Peugeot 8Aa. Camshafts, piston rings and some bearings were interchangeable.

United States

In 1915 representatives from the Wright Company approached the French government to negotiate a license for the Hispano-Suiza 8 engine which was then under test. The French government refused to grant a license and instead offered the Peugeot 8Aa as an alternative. Ultimately the Wright company negotiated a license directly with Hispano-Suiza in Barcelona. The Wright company went on to produce 8,976 Hispano-Suiza engines during World War I.

United Kingdom

The first British orders for the Hispano-Suiza 8 engines were placed in August 1915, shortly before the first order from the French government. Production in the United Kingdom was handled by Wolseley Motors who produced modified versions as the Viper. A total of 3,050 engines were built in the United Kingdom during World War I.

Italy

SCAT, Itala and Nagliati all took out licenses for production of the Hispano-Suiza 8. Italian production of the engines during World War I numbered 2,566 units. Most of the Italian built engines were fitted to SPAD S.VIIs and SPAD S.XIIIs imported from France.

Czechoslovakia

In 1922, Škoda obtained a license for the 300 hp variant which they produced throughout the 1920s.

Japan

In 1918, Mitsubishi acquired a production license from Hispano-Suiza.

Spain

During World War I, 112 Hispano-Suiza 8 engines were built by La Hispano-Suiza in Barcelona.

Switzerland

In 1917, Sauer reverse engineered a 150 hp Hispano-Suiza engine. The Swiss engines were initially unlicensed copies however after World War I Sauer negotiated a license with Hispano-Suiza.

USSR

Between 1920 and 1922 the Soviets license built 36 examples of the 220 hp Hispano-Suiza 8 model. From 1921, the Soviets designated the 220 hp model as the M-4. Other aero engines added retrospectively to the Soviet's designation system included the RBVZ-6 (M-1), the Rhône 9J (M-2) and the Renault 12F (M-3). The Soviets also built 331 examples of the 300 hp Hispano-Suiza 8 variant as the M-6. The M-6 was in production from 1925 to 1932.

Variants

Some data from: British Piston Engines and their Aircraft
Note: Hispano-Suiza company type numbers were prefixed by HS- or written in full as Hispano-Suiza Type 31, but military designations used the conventional system of Hispano-Suiza 8 A b r, thus Hispano-Suiza 8Abr.
;8A :, initial production and test engines, with few applications, including early Nieuport 14s.
;8Aa
;8Ab
;8Ac
;8Ad
;8B
;8B twin :Coupled 8B engines
;8Ba
;8Bb
The 8B, 8Ba and 8Bb were used to power the earliest versions of the S.E.5a, along with the 8Bd, the SPAD S.XIII, front-line active versions of the Sopwith Dolphin, and several other Allied aircraft types, with its gear reduction easily identifiable in vintage World War I photos, from its use of a clockwise rotation propeller.
;8Bc:, compression ratio of 5.3:1, reduction gear 0.75:1.
;8Bd:, compression ratio of 5.3:1, reduction gear 0.75:1.
;8Bda
;8Be:, compression ratio of 5.3:1, reduction gear 0.75:1.
;8BeC : The 8Be fitted with the SAMC Model 37 cannon, or a similar weapon, as an engine gun firing through the propeller boss. A reduction gear equipped power-plant with a resultant clockwise rotation propeller like the 8B, produced at 2,100 rpm. Two known weapons fitted were the SAMC with a rifled barrel and a smooth-bore cannon firing canister ammunition. The moteur-canon could fire a single shot at a time through the hollow drive shaft without propeller interference. This cannon mount required an "elevated" intake manifold design, bringing the intake "runners" straight off the inner surfaces of the cylinder banks to the updraft carburetor's plenum chamber. The engine was used on the SPAD S.XII.
;8Ca/220: engine gun-equipped at 2,100 rpm with 5.3:1 compression. Given the company designation HS Type 38
;8Cb/180: engine gun-equipped at 2,000 rpm with 4.7:1 compression. Given the company designation HS Type 44
;8Cc/220: engine gun-equipped at 2,100 rpm with 5.3:1 compression. Given the company designation HS Type 44
;Hispano-Suiza Type 40:
;Hispano-Suiza Type 41:
;8F
;8Fa
;8Fb
;8Fd Special
;8Fe
;Wolseley W.4A Python I
;Wolseley W.4A Python II
;Wolseley W.4A Viper
;Viper II">Wolseley Viper">Viper II
;Wolseley W.4B Adder I
;Wolseley W.4B Adder II
;Wolseley W.4B Adder III
;Wright-Hisso A:Wright-Martin built Type 34/HS8Aa at 1,400 rpm and 4.72:1 compression.
;Wright-Hisso B: 4-cyl in-line water-cooled
;Wright-Hisso C: geared A
;Wright-Hisso D: geared A with engine gun
;Wright-Hisso E: at 1,700 rpm and 5.33:1 compression
;Wright-Hisso E-2:
;Wright-Hisso F:
;Wright-Hisso H: , based on the Type 42/HS8F
;Wright-Hisso H-2: improved 'H'
;Wright-Hisso I:
;Wright-Hisso K: H with 37mm Baldwin engine gun
;Wright-Hisso K-2:
;Wright-Hisso M: experimental 300 hp
;Wright-Hisso T:
;Wright-Hisso 180 hp V-8: direct drive
;Wright-Hisso 220 hp V-8: geared drive
;Wright-Hisso 300 hp V-8: geared drive
;Wright-Hisso 300 hp V-8: geared drive
;Wright-Hisso V-720
;M-4: Soviet produced 8Bb
;M-6: Soviet produced 8Fb
;Mitsubishi-Hispano-Suiza 300 hp engine: Imperial Japanese Army produced 8Fb

Applications

;200 HP
;300 HP

Engines on display

Spain.