Evening star., 1927-05-01
SUGGEST CAUTION
IN AUTO REMEDIES
Experts Say Effect OF
"CureS" Are often Worse
Than First Malady.

Before applying a remedy to any
automobile i'll, be sure the remedy is
the correct one. No remedy is right
merely because it has been tried by
thousands of automobile owners. on
the contrary, the effects frequently
are more serious than the original
malady.
This Is the most important lesson in
car care still to be learned by motor
lists, and, in driving it home, engineers
and mechanics are aiming partiCu'
larly at the so-called remedies con-
cocted in the minds Of the ineXpe.
rienced and given credenCe because
of wide practice.
Experienced repairers know there
are many remedies TO be avoided. one
is the practice of using a heavy grade
of oil when piston or piston ring
trouble has developed. This serves
frequently to silence slap or TO pre-
vent excessive oil pumping, but it
carries with it certain troubles Of its
own. The least Of these is the pos
sibility that the cylinder walls will not
have sufficient oil when the engine is
being driven at top speed. A certain
amount of oil pumping is advisable
at high speed to take care of the maxi
mum expansion of the pistons, other
wise the pistons may bind in the
cylinders.
Provide OiI-Mist.
There are on the market several
devices intended to provide an oil-mist
in the cylinders, by admitting a little
oil.laden air through the intake mani
fold. One advantage claimed for these
devices is that the oil forms a seal at
the pistons so that gases cannot so
readily force down into the crankcaSe.
This means more power and less oil
diiution. Clearly, then, it is an ad-
vantage to have a little oil get past
the rings into the cylinders, at both
high and low speeds. To use heavy
grade of oil, therefore, may mean too
little cylinder wall fabrication at all
times.
When the engine is cold the heavy
oil is CONCEALED and will not flow and
splash readily. When the engine is
hot the oil will be too heavy to
squeeze past the rings. which fit very
tight, because of the increased eXpan-
sion created by friction.
Remedies for engine knocks are
blamed for much of the trouble motor
lists have with their power plants.
There is one case on record where, in
an effort to locate one knock, an own
er managed TO add three others.
Tinkered Too Much.
This was the result of having the
engine tinkered with too much. BY
the time the original knock had been
traced to the water pump shaft the
engine had been tampered with to a
point where it was actually out of
balance. The reboring process had
fn
new pistons had not been carefully Sc
lected as to weight,
Not all remedies" are as bad as
this, but they are often bad enough.
One of the most unfortunate remedies
for a piston slap is TO line up the
connecting rods. This process actually
makes them softer and more inclined
Ito bend out of line again. Connect
ing rods are built SO as to bend o
little under great strain, as when the
car is being driven slowly up Hill IN
high gear. In almost every car in
service the rods are a little out of
line. when measured with an align
ment instrument. To line them up
frequently means weakening them.
In looking for trouble, many car
owner has found himself collecting
lot of new trouble. Almost invariably,
a mechanic VIII set out Ior test hllI
when hef is looking for trouble. and
test hills have given motorists more
trouble than they ever have helped
to remedy.
Test Is Favored.
A favorite carburetor test is to allow
q car to come to a creeping speed at
the bottom Of the test hill and then
observe conditions as the accelerator
is pressed to the floor. A good mix
ture will permit the average car to
climb steadily, provided everything
else is in proper working order. If
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