Los Angeles herald., 1910-06-12

Some people are prejudiced against
air cooled engines, a result of failures
when air cooling was in its infancy,
but don't forget that this art has pro-
gressed most rapidly.
The necessary conditions in designing
and operating an air cooled motor are:
First-A free and almost immediate
release Of the exhaust gas at the end of
the power stroke.
Second-A liberal area of radiating
surface.
Third-A normal mixture which burns
and expands the gas as rapidly as pos
sible.
Fourth--An early ignition.
The first two release the source of
heat as rapidly as possible as soon as
the expanded gas has completed its
work of driving the piston, the third
prevents the excessive heat which is
produced by an over-rich. mixture burn
ing until the piston has completed its
exhaust strickland which Is wasted
energy-while the fourth tends to con-
fine the greatest heat to the cylinder
head.
If you drivers Of water cooled cars
will bear these essentials in mind, you
will get better results. You can't make
your motor give better results than the
air cooled, but 1t will stand more act
ual abuse.
The engines used for several years on
the Franklin and Middleby cars are the
most successful type Of the air cooled.
In this design port is cut through the
side of the cylinder in a position where
1t Is uncovered by the piston just at
the end of the power stroke. The pis-
ton uncovers quite a large area of this
port in a very short time, allowing ali
the exhaust gases to escape almost in
stantly, the rapid escape of the exhaust
at this point meaning that the hot gas
remains in contact with the cylinder
walls only one-Quarter of the time, and
the heat taken up by the cylinder is at
a minimum. The radiating fins, or
flanges, are as large as foundry prac-
tice will allow, giving the maximum
radiating surface for disposing of the
heat.
The fact that If the fins, or 1anges,
are cast too large or too thin they have
tendency to fracture, and that If too
close together the air currents do not
pass readily between them has limited
the size of air cooled cylinders to about
four and one-half inches, the area of
the radiating surface which it is possi-
BILE to secure increasing much less In
proportion than the size of the cylinder.
It Is possible to overhead any motor
If the mixture be too rich, the work too
arduous, the cooling device defective,
or II IneT6 De Il ldCk Oh 4 Il6
first symptom is a loss of power. This
loss of power is shown by the slowing
Of the engine If spark and throttle are
left in one position, or if on opening
the throttle the engine doesn't respond.
If this condition is allowed to go on,
the motor may stop, the expansion of
the pistons locking them fast in the
cylinders.
If an air cooled motor is overheated
l.. or.oI. u rT116
it is ell heated evenly, while in q wa
ter cooled design the cylinders are apt
to be scored. This Is due to steam
collecting in spots between the cylin-
der and water jacket, and as the steam
will not remove the heat. these spots
may become red hot, and are easily
marked
1Ixicks over" after you have discon-
nected your electric current that it Is
essentially overheated. These extra
explosions are almost always due to
minute incandescent particles, gener-
ally of carbon, but they may be small
spiculae projecting from a cylinder or
piston, or even hot points of the spark
plugs.
The air cooled engine does not neces-
sarily use any more oil than the water
cooled, though some drivers waste
more. There is no occasion for an air
cooled motor filing the whole street
with smoke-all that smoke is simply
wasted OIL and has absolutely no eff
feet on the cooling qualities of the mo-
tor. Any gas engine cylinder must
have the necessary amount of lubrica-
ton, and this is indicated by a faint
trace of smoke at the exhaust AS
soon as this appears continually, fur
ther increase In the supply of oil is
simply waste.
Most all of us use more oil than is
required, I do myself, particularly in
new cars before they are run in.'