Evening star., 1941-01-23
By JOSEPH S. EDGERTON,
Star Aviation Editor.

tary aviation projects, the develop
ment of a giant 1000 horsepower
in-line. uid-cooled airplane engine
which actually will be more powerful
than any yet built, has reached the
production stage.
The result of a long research and
experimental program which began
even before the present world emer-
gency, the 000-horsepower giant
can be put into production whenever
the Government gives the word, ac-
cording to officials of the Allison
Division of General Motors Corp
now engaged in production of the
1000 horsepower Allison liquid
cooled engine under United States
and British contracts totaling $685.
100000
, Although many of the parts of the
/ Allison 1000 horsepower engine
! could be used in its giant sister, pro-
duction of the big engine would
virtually necessitate the construction
of entirely new plant facilities and
tooling, it was explained, since all
facilities which are now being pro-
vided are necessary for completion
of existing contracts for the 1000
horsepower engine.
Requires Doubling Up"
The big engine is obtained by
doubling up" the 000-horsepoWer
type. The smaller engine has two
banks of six cylinders each. driving
single crankshaft. The 1000
horsepower engine has four banks of
cylinders in an X-shaped pattern,
driving two crankshafts.
The 2000-horsepower rating is
only nominal, it is said and the
giant engine actually produces con-
siderably greater horsepower under
ideal conditions. This also is true of
the present production engine, which
though nominally "1,000rhorse
power engine" actually turns out
1l50 horsepower at its most efficient
operating altitude.
Although the ,2.000-h horsepower
engine is available for production,
however, there is no assurance that
orders will be forthcoming in the
immediate future either from the
United States or England. Neither
the airplane or the propeller capable
of handling this tornado of power
has yet been designed. Experimental
work along these lines is in progress,
it was admitted
With little more frontal area than
the existing 0-horsepower engine,
the new giant should make possible
the fastest airplanes ever produced
for military purposes, Allison en-
gineers believe. far outstripping the
performance of the new Navy
Vought- -Sikorskv Eau fighter built
around the new 1,850-horsepower
Pratt g. Whitney radial, air cooled
engine, which presents very much
greater frontal area to create drag
and slow up airplane speed.
AS a matter of fact, liquid-cooled
engine enthusiasts are willing to pit
the best of the Allison powered
1,OOO-horsepower pursuit airplanes
against the new F4U in test of
efficiency and say they are conf
dent, if the walls of military secrecy
could be broken down. that the re-
suits of such a test would be star
tling.
Comparison of Speed.
With nearly 100 per cent more
horsepower (since the big Pratt &
Whitney actually is caoable of pro-
Gucing around 1000 maximum
horsepoverr the Eau has no more
n
the Bell Airacobra P-39 Army pur-
suit airplane, built around the 1000
horsepower Allison, it is claimed.
The nearest approach to official
figures available shows a speed of
3o5 mile per hour for the 1000
horsepower Airacobra and about
402 miles per hour for the Eau with
its 1000 horsepower. Aircraft en-
gineers here are of the opinion that
an honest test would show the ac-
tual difference to be even less. They
argue that most of the F4U's 1000
horsepower advantage over the Air
acobra is lost in pulling the larger
engine through the air and in the
increased size of the airplane neces-
sary to carry the larger engine and
the larger gasoline tanks necessary
to keep it going.
This is the cruX of the argument
between supporters of the air
cooled versus the liquid-cooled air.
plane engine. The Allison engine
in the Airacobra presents only the
same frontal area as the pilot;
that is, its width is no greater than
that of the pilots shoulders and
it's depth no greater than his seated
body. Thus, the fuselage can be
tailored" to fit the pilot and engine
will conform The r-cooled, on
the other hand, has its cylinders
stuck out in a circle like the spokes
of a wheel, and must present its
round face to the air-floW for COOL
ing and other reasons.
Claim Liquid Cooled Advantage.
Claiming their 1,000-horsepower
engine, in a properly designed air.
plane. to be productive of almost
the same efficiency as the 1000
horsepower air-cooled in the much
larger type of airplane necessary
to carry it, liquid-cooled aircraft
engine authorities declare that,
from the standpoint of all-around
efficiency. the air-cooled engine is
far behind the liquid-cooled.
Added horsepower doesn't nee
essarily mean added speed" they
point out. The racing automobile
driver of today doesn't tell you how
big his engine is. He takes pride
in the fact it's no bigger than a
sewing machine. If you could fly
an air-cooled engine sideways, it
might be more efficient. But you
can't It's got to stick its big round
face right out in the wind or you
can't cool Il. When you shoot a
clay pigeon, you never expect it to
travel with its fiat face forward
1t skins sideways; the only way it
can be thrown any distance"
For this reason, aeronautical en-
gineers expect that the 1000 horse
power in-hne, lquid-cooled engine