Hispano Suiza V8A
In 1915 designer Marc Birkigt, working for the Swiss-Spanish firm Hispano Suiza, created one of the most successful aviation engines to appear at the beginning of aviation. Taken from its origin in the 8-cylinder motor-car engine, and after some refinement and modification according to the specific requirements of aircraft at the beginning of 1915, the HS-8A was tested. Its design was a basic 8-cylinder V-type. For the first time solid aluminum cylinder blocks were used; each 4-cylinder head and valve system had integrated cooling jackets, and steel sleeves were threaded directly into the block to form the cylinder housing. This innovation made construction quite easy, and yet at the same time offered the necessary rigidity. Apart from that, the production of such an engine appeared to require sophisticated technology. Testing of the engine proved the rightness of the designer's ideas and opened up the prospect of its perfection in the future.
The Hispano Suiza appeared to be more efficient in comparison with rotary engines of similar power, and precise machining was not so critical to its manufacture. During trials the Hispano Suiza was subjected to a severe bench test, and the firm received much censure from the military, but in spite of it, it was soon ordered in massive quantity. The most modern French fighter, the SPAD VII, and also the British RAF S.E.5, which would at last offer effective resistance to the growing air-power of Germans, were designed specifically for the Hispano Suiza V8. No failure of the engine was allowed to hinder development of these machines; but another problem was that of sufficient production factories could not satisfy the frantic orders from the Front. Soon, production licenses for the Hispano Suiza V8 was purchased by Great Britain (built by Wolseley in its Birmingham plant), Russia, and Italy. About 6,000 Hispano Suiza V8 were produced overall.
The Hispano Suiza V8 was used by such types as the SPAD VII, RAF S.E.5, Sopwith Dolphin, early SPAD XIII and the RAF S.E.5a, and various others. In due course, in describing the Hispano Suiza V8, historians termed it the "Rolls Royce Merlin of WWI". Together with a subsequent development, the Hispano Suiza V8B, the engine could hardly fail to be considered a major technical achievement of the Great War era, and it played an important role in the victory of the countries of the Entente in the battles in the air.

Type 90° Vee liquid-cooled engine
Cylinder 8
Displacement 11.76L
Compression ratio 4.7
Bore 120mm
Stroke 130mm
Dry weight 202kg
Power output 112kW
R.P.M. 2000
Torque 64kg/m
Length 1190mm
Width 810mm
H eight 770mm
Fuel consumption 0.23kg/(hp·h)
Oil consumption 0.014kg/(hp·h)