Hispano-Suiza 8Ab
In 1915 the designer Marc Birkigt, working at the Spanish-Swiss firm Hispano Suiza, created an extraordinarily successful water-cooled engine which was widely used by the aviation of many countries.
This engine consisted of a V-type eight cylinder configuration constructed with solid cast blocks. The first version of the engine produced 150 hp and for 1916 it was very modern and satisfied all the requirements of the military. The Hispano Suiza was fitted to the British S.E.5 fighter, and also to the French SPAD VIIñ.1, the most modern aircraft designs of that period of the war.
However, the perfecting of the engine did not end there, and the more powerful 180 hp Hispano Suiza 8Ab soon appeared, and a little later, the 200 hp Hispano Suiza 8Ba, with increased engine speed and a reduction gear. Some structural failings which were evident in earlier versions of the engine were remedied, and in 1917 the new engines were fitted to the RAF S.E.5a, the best British fighter of WWI. The French Air Force also soon received a new fighter with this engine: the SPAD XIII which replaced the largely obsolete SPAD S.VII.
The Hispano Suiza became the most numerous and widely used water-cooled engine of WWI. There were more than 40,000 units produced in total, in Great Britain, France, Spain, Russia and the United States of America.

Type V-figurative water cooling
Cylinders 8
Displacement 11.76L
Compression ratio 5.3
Diameter of the cylinder 120mm
Stroke 130mm
Dry weight 230kg
Power output 180h.p.
R.P.M. 2100
Length 1310mm
Width 850mm
H eight 870mm
Fuel consumption 0.5kg/(hp.h)
Oil consumption 0.029kg/(hp.h)