The Knoxville independent. [volume] (Knoxville, Tenn.) 1894-current, 1918-09-07
INFERIOR OIL IS
MOST EXPENSIVE
LoW-Grade Lubricant Fouls
Spark Plugs, Breeds Carbon
and Other Trouble.
LITTLE POWER IS DEVELOPED
Among Other Annoyances From Car
ben Collection Is Knock In Engine
Raising Compression to Point
Where Preignition Occurs.


Have you surplus of carbon about
your car-especially in the cylinders?
Does it clog up the combustion cham
Der, stick on the valves and make
them leak, and issue in black smoke
from the exhaust, to the accompani-
ment of sundry knocks? Better con-
serve your carbon and burn it oil, for
there is a carbon Hoover in sight and
he may cut down on your rations-of
oil and gasoline.
Owing to the high price and the
difficulty Of getting supplies of good
oil, poor grades are substituted right
along. In one case which came to my
attention an owner was having trouble
with the car, says writer in an ex-
change. There was knocking and the
spark plugs fouled, causing irregular
running of the engine. The owner had
been using high-grade oil. He could
not get his particular brand and
bought another at the same price, sup
posing the quality to be the same be-
CIuSC Liz pIlNC w SSs w lSh lllS tloublS
was studied it was found that, al
though he paid the same as for high
grade oil, he got much inferior grade.
He was advised to change, did, and his
trouble ended. To get the good grades
now it is necessary to pay consider
ably higher price than year ago.
w;II Mot Stand AAa+
Some grades Of oil will not stand
the intense heat of the combustion
chamber, nor even the temperature of
the cylinder walls and piston. The
oil burns and forms carbon. This car
bon collects on the insufator Of the
spark plug and forms path for the
| ignition current over the insulator,
called a short circuit. This causes mis-
firing and the engine runs very jerky
and is altogether unsatisfactory.
This fault can be corrected easily
by cleaning the spark plug, but often,
with q poor grade of oil, it is neces-
sary to do the cleaning every 30 or
| 100 miles.
Carbon also collects on the seat Of
the exhaust valve, making II impos-
Sibie for the valve to close entirely,
Z isay * g-Tztg ffFs
I She effect 6f
III gEiaT very little or no power is de-
/ yeloped in tho cylinder, and also mis-
firing anu irregular running, the same
as with the short-circuited spark plug.
In some cases this can be corrected
easily by taking out the valve cap and
disconnecting the valve spring, when
the valve may be removed and the car
| bon scraped from valve and seat with
knife or other instrument. Then q
slight grinding in of the valve will
give a tight joint.
Knock in Engine.
| Another annoyance which comes
! from carbon accumulation is a knock
In the engine, which results from the
decrease In the size Of the combustion
chamber in proportion to the accumu-
lation. This raises the compression to
point where preignition occurs.
Hence the knock. To overcome this
trouble it is necessary to remove the
cylinders from the crank case and
have the carbon scraped out. Where
the cylinder head is removable that OBJ
viates the necessity of removing the
cylinders.
Temporary relief may be had by
having the carbon burned out by the
oxygen process. Liquid carbon remov-
ers help out, but are not so good, be-
cause the carbon which is loosened
goes to the muller, where it is likely
to clog the small holes and materially
decrease the power of the engine by
preventing q free exhaust.
While it is possible to overcome
these troubles, it is much better to
buy good grade of oil in the begin
ming and prevent them.