net
Equally interesting in its way was the Fairey Battle
powered with the Rolls-Royce " Exe " engine. This power
unit, rated at 1,200 b.h.p at 4,000ft, was of 22-litres capa-
city and comprised 24 cylinders arranged in banks of six
in the form of an X. The really interesting aspect of this
engine, in the light of traditional Rolls-Royce practice, is
that it was pressure air-cooled and ported with sleeve
valves (the latter providing experience for the 3,500 h.p.
Eagle of to-day). The "Exe " was a quite successful engine
but it was not taken beyond the prototype stage
because at that time—September, 1938
it was realized
that the Merlin was going to absorb the whole of Rolls-
Royce production potential in the near future.