, 1918-08-15
PROPER CARE IS
DUE TO MUFFLER
Purpose of Device Is to Diminish
Noise of Exhaust and Permit
Gas to Escape.
CL0GGING SHUTS OFF POWER
It Must Be Taken Apart to Clean and
All Carbon Deposits Removed
Ream Out Small Holes With
Three-cornered File.

"Why is a muffler used on a carr"
Is a common question among motor
lists, and they sometimes add: 'What
care does it need and to what trouble
is it subject?"
The purpose of the muffler is to d.
minlsh the noise of the exhaust. The
gas escapes from the exhaust valve at
high pressure and the resulting noise
Is disagreeable unless silenced. 1t
is necessary to reduce the pressure
from each explosion and to allow the
gas to escape so that a great deal of
its force is dissipated and its %disjoint-
ed nature completely changed. The
gas then passes out quietly with only
a slight %pulsation or throbbing.
The methods by which this is
brought about are very simple. A gas
passing along an ordinary pipe would
be slowed down and spread out. This
arrangement would require too long
a pipe. So battle plates are used to
a the gas turn corners and force
its way through small holes in the
plates. In some mufflers the gas en-
tiers an expansion chamber. All this
time 1t is losing heat and so contract
ing and thus 1t slows down more and
more. The final effect is, as stated, to
have the gas issue from the muf-
fer in a steady, quiet manner.
Leave Muffier Alone.
The care of the muller is to leave
1t alone until 1t becomes clogged. 1t
does its work without any attention
and requires nothing from the driver.
The only time we think of 1t is when
we wish to find out If the engine is
missing explosions. Then we cut out
the exhaust. Do this cautiously on the
road, as there are laws against 1t in
many localities. If the sound of the
exhaust Is not sufficiently loud 1t may
be increased by retarding the spark
and opening the throttle part way.
The sound of each cylinder will then
be brought out distinctly and any
weakness will be noticed Immediately.
c~Iosglng Only Trouble.
About the only trouble to which the
muller is subject is that 1t becomes
clogged with SCOT. This may be caused
by too rich a mixture from the carbu-
refer, lnulcateu Dy Dldck SMOKE from
the exhaust, or 1t may be caused by oil
working up on top of the pistons, Civ
ing the blush white smoke character
istic of too much lubricant. Another
cause is where the carbon has been
scraped loose from the cylinders, but
allowed to fall on the piston. This is
carried into the muller, and so helps
to clog. In order to clean 1t, 1t must
be taken apart and all the carbon de-
posts removed. If the small holes are
closed with SCOT they must be reamed
out with n three-cornered file or. bear
ing scraper. The parts are then reas'
sembled carefully and replaced on the
car.
1t is easy to tell If the muffier is
clogged where there is a cut-out. Rur
the machine up n fairly steep hill. II
the car speeds up with the cut-out
open it shows that the muffier Is
clogged. A well-designed silencel
should not cut down the power of the
engine more thar 8. per cent. This diff
ference will hardly be noticeable on ar
ordinary hill. So the fact that the cal
slows down would indicate back pres
sure due to clogging