The Washington herald., 1921-02-27
Causes of Engine Overheating Out
lined, With Suggestions for
Overcoming Them.

1t is inevitable in a somewhat
complicated mechanism such as the
modern motor car that there should
be certain definite ills afflicting va
rious parts thereof, and the man
who wants to or perforce must care
for his own vehicle must be letter
perfect in these standard ills and
must know how to cure them.
One OF the common troubles that
we have named standard Ills" fr
overheating the engine. As II hap
pens, overheating Is "a symptom
rather than a basic trouble. That
Is to say. it Is caused by certain
definite failures in the mechanism
and the owner who learns just what
these basic troubles are and is able
by process of elimination to trace
back to the real cause can master
the trouble without difficulty.
AS pointed out before, heat is a
form of power. If il were not for
the necessity of maintaining a flm
of oil between the various moving
parts of the automobile engine in
order to keep the friction present
within reasonable bounds there
would be no reason why the power
plant should not run very much
the need for preventing the break
.ing down of the oil film by excess
sive heat IL is necessary to have a
cooling system around the cylinders
fIled with water. II the heat, in
spite of this precaution, does get
beyond a certain safe maximum the
oil Is burned up, the intense fric-
fion Of metal parts moving against
metal increases the heat to a point
where the parts seize and the power
plant is ruined.
Not Confined to Summer.
~ While overheating is not a condi-
tion confined to the summer season,
nevertheless it is more prevalent
during the hot weather. just when
we use cars most continuously.
Now 1t happens that overheatins
is bad for the engine. and repeated
doses of II may ruin even the
!. most important parts of 1t. Take
uotice. therefore. that this Is an
other case where the ounce of pre-
[vention Is worth the pound of cure
Almost any driver of a car real
s ICES that IL he runs his vehicle for -
considerable distance on a retarded
spark overheating will ensue. The
water will boil and steam will issue
from the radiator overflow. 1t is
doubted whether very many read
ers have ever stopped to consider
Why 1t Is that running with a late
spark causes the condition of ex-
cessive heat. With a retarded spark
the explosion occurs when the pis-
, ton is descending. This means that
more of the cylinder wall is exposed
to the heat of the combustion and
consequently more heat is passed
through the walls into the cooling
water. which gets hotter and hotter.
When the spark Is advanced COM
paratively little of the cylinder wall
area Is exposed to the flame of COM
bustion and less heat Is sent through
the walls into the cooling water.
Most drivers have noticed that II
they have to drive up a considerable
grade on a retarded spark to pre-
vent knocking In the engine, by
the time the car gets to the top
of the hill the engine Is hot and the
eooling water Is actually boiling.
Investigate Knoeking.
when an engine has this charac-
tsristic Of knocking when the spark
Is advanced even q little 1t will be
we'll to investigate and see IL the
fundamental cause of the knocking
can be discovered. II this funda-
mental cause can be found and
cured II will be possible to advance
the spark enough to prevent ex-
cessive heating on grades or in sim
liar circumstances. Here, then, is
the frst cause Of overheating.
Now It need scarcely be said that
|R anything happens in the cooling
system to stop or impede the flow
Of the water the nuid will quickly
become overheated and boil. The
only thing that keeps the water In
condition to perform any cooling
function anyway Is Its constantly
Perhaps the nrst thing
10 DO when overheating develops Is
TO take q look into the filler neck
Of the radiator. II the wtaer seems
10 be flowing all right, then we
must look farther. II the water Is
then some obstruction in
khs cooling system demands imme-
6iats attention.
Il the cooling system II Of the