New-York tribune., 1921-11-20
Keep Mumer
Clean and No
Cut-Out Needed
Located Under the Car and
Out Of Sight, This Impor-
tant Part of the Auto Is
Very Rarely Attended To
By H. Clifford Brokaw

Technical Director West Side Y. M.
c. A. Automobile Schools
One of the parts of an automobile
most neglected by many owners and
drivers is the mufflcr, As boy with
dirty face puts off the cleaning up
process just as long as possible, so the
motorist with a muffler that needs at
tention procrastinates and thinks per-
haps he will FIX it up tomorrow. And
tomorrow never comes. But to-day is
always here with it's greater use of
gasoline and various other complica-
tions that dirty muffler causes.
The muffler is located under the car,
and being out of sight is usually out of
mind. 1t is therefore often> neglected
or misused. And yet it ought not to
be. The muffler is placed on the end
of the exhaust pipe Of the engine SO
that the driver of an automobile while
taking pleasure himself does not
wholly deprive others of it.
Let US consider the use of the muf-
fer. The exhaust valve opens while
the burned gas is still under pressure
of from twenty-five to thirty pounds
per square inch. If this were ex-
hausted directly into the air the re-
sulting noise would stife conversation
in the car, annoy everybody along the
street and quickly get the driver into
trouble with the police. The mufier
prevents all this. 1t provides & cham
her in which these exhaust gases may
expand and cool somewhat and at the
c. ANA l, l.xy
allowing it to leak out slowly through
number of very small holes, instead
Of letting it loose in one "big noise"
The "Cut-Out" Valve
In the early history of the auto
mobile muff1ers were not used and
everybody for blocks around knew when
an auto was coming. AS the auto
mobiles increased in number this be-
law Then they sought, indeed had
been seeking, means of sitting the
sound. In the early muff1er there was
trouble because the gas would back up
IN the cylinder and decrease the power
of the motor. 1t was thought there
was no way to decrease the sound with
out decreasing the power; therefore
the manufacturers devised a valve to
"cut out" the muff1er on the car when
ever extra power was desired.
Sometimes the back pressure was
so great as to interfere when driving
through heavy roads or up hills. The
"cut out" let the gas exhaust directly
into the air instead of going through
the muffer. At the present time near
ly every city has a law prohibit
ing the use Of "cut outs"
AS matter of fact, those we'll post
ed on automobile engines understand
to-day that the "cut out" is absolutely
unnecessary on a modern car if the
muffler is kept in proper condition.
Muffier manufacturers have been able
to produce design in which there is
no back pressure at all. For this rea-
son manufacturers discourage the use
Of the "cut out" on their cars, and
some of them will no longer install
one except as an extra"
The average driver, however, does
not know that his nuff1ler needs as
careful attention as any other part of
the mechanism, and so he neglects it.
In these days of noiseless cars it re-
quires a great number of very small
holes inside the mutf1er. These become
clogged with SCOT or carbon from the
exhaust. The deposit collects very
rapidly, especially when the grade of
oil used is poor or too much oil is
used. 1t. also results when the car
buretor is adjusted to give too rich
mixture.
Openings Become CIogged
When these small openings become
clogged the exhaust gases cannot es-