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.