Evening star. [volume] (Washington, D.C.) 1854-1972, 1931-06-28
SILENCE STRESSED
IN AUTO MODELS
0utWeighs All Other AID.
vanceS in New Lines Ap-
pearing This Week.
Special Dispatch to The Star.


DETROIT, June 27.-Silence, q
priceless quality in automobile oper-
alton, Is coming in for added stress by
makers who are introducing seasonal
new models at this time. In two new
lines of cars appearing this week, and
one other line due a week hence, the
claims Of silence and Smoothness out
weigh all other advances that the new
models embody.
The public has been hypercritical re-
garding silence of cars for almost a
decade With this in mind, the manu-
facturers and the engineers have been
straining for years to attain the ulti-
mate Objective noiseless car.
Perfect Precision.
One reason for it is that silent opar-
alton is coupled with perfect precision
in engine building. With precision,
commonly reckoned to thousandths of
an inch in the At of bearings and
parts. IS associated absence of friction,
and therefore the smooth, velvety &C
ton of reciprocating mechanism that
every man wants in his new car.
One way it has been accomplished
was by reduction of metal to metal
contact in every part subjected to
strain.
Vibration. the foe Of smoothness,
engineers say, is due to the car shak-
ing as the power from the engine is
applied. The first cars that were built
were mounted on springs and had
engines that were bolted rigidly to the
frames. That was one reason why they
were noisy and rough" at certain
periods Of the speed range.
Engineering effort over a period of
years has been directed toward tracing
the causes and then canceling them
out. II has become a continuous pro-
cess from numerous angles applied
both to the power plant and chassis.
On the power side. the engineers have
developed engine balance by the use
Of CONFERENCE.-The on crankshafts, add
ing a flywheel in front as well as be-
hind, and by neutralizerS and other de-
vices with fancy names. intended to
check out the elusive noises.
Bearings Increased.
They have increased the number Of
bearings in engines from three to five
and seven. nine and even eleven in
some cars. They have built multi
cylinder engines in which the power
impulses overlap with high frequency
equivalent almost to a straight line as
the revolutions go up on the speed
chart.
With these have come the intake ST.
lencer, applied on eight-cylinder en-
gines to stop power roar"
For the engine itself and its anchor
age in the chassis, modern design pro-
videS cushioning in place of the rigid
boiling that once served to hold mo-
tors firmly in position. To that end. 1t
Is the accepted idea now to mount,
cradle or float the source of the power
in live rubber.
More Rubber Used.
To make rubber serve this purpose
and also to Withstand wear in other
parts of the chassis for which it also
is used to deaden sound and shocks,
has hen a problem. Research, how
ever, Is conquering it. The result is
that the automobile industry Is using
more rubber, aside from tires, than it
ever did before in fabricating the mod
ern type of chassis.
Last year the automobile builders
again were the biggest customers for
crude rubber. They used 8,774 900
pounds Of it. Tires, Of course, account
ed for the greater part of the increase
TO 81 per cent of the crude that went
into car usage. But the chassis re-
quirements were proportionately large.
(Copyrisht, 1891. by North American News
paper Alliance, Inc.D