Great Falls tribune. [volume] (Great Falls, Mont.) 1921-current, 1922-06-18
Barney ldff@d says:
WHEN THE ENGINE is NOISY

Noisy machinery wears fast. The
noise alone is unpleasant, to be sure,
but it means wear, wear, wear. 1t
does not matter what is producing the
noise, whenever metal parts came TO-
gether go that a noise is produced wear
is taking place at the same time. Whlie
our passenger car engines are remark
ably quiet when compared with the en-
gines of ten years ago, the engineers
are striving for still further quietness
and the maintenance of that absence OF
noise for a long time. Some drivers
feel very uncomfortable when sitting
behind and engine that has even II
slight tap, tap, tap in 1t. 1t is no.
normal. for the driver thinks only OF
the engine as it was when new. a
smooth running, velvety thing that
costs little to operate. When 1t gets
noisy he begins to worry for he does
not know what that noise might brlng
eventually in the form of a repair bill.
Some noises are danger signs, 'others
shouldn't bother any driver.
Most of the noise OF an engine comes
from the valve gear because there are
more moving parts to this system thah
to any other. The valve gear consists
of the cam, the push ROD or tappet;
valve TOu, TOtheI aim tici
enpines), valve and spring. In such a
train of moving parts there are three
or four places that may wear ana IN
some engines there is no provision tor
lnbricating these parts automatically.
Of course. the camshaft is inside the
crankcase and gets plenty of OIL and In
modern engines the tappets or push
rods also get a good supply, but not
always the valve stems, and rocker
arms, In this age of development there
are still some overhead-valye engines
in which the rocker arms must be oiled
by means Of an oil can. In others
there are automatic oilers either drip
feeders or wick feeders.
Side Play
Noise may develop because OF side
play in a tappet or push rod. This is
q very common noise and If the wear
is great enough it may knock. Usually
il is in the form Of a clicking sound
that occurs ever time the valve IS
opened and every time the push rod
drops down with can movement. The
way to locate this noise is to feel each
push rod for side play and the only
remedy worth while is to replace the
worn parts. This applies as well to
rocker arms in overhead valve engines.
If there is side play in them they slap
back and forth and produce a very UNI
comfortable sound. If the rocker arm
bushings are badly worn you may get a
knock in addition because then the arm
wabbles on its shaft.
If valves do not fit the guides well
they may slap and a similar slap is
produced if the spring pressure is too
great or if the valve head is warped
and does not come to its seat evenly.
A valve slap sometimes Sound like a
tappet click, but the latter is so much
more common that it is first suspected.
A valve slap may go away if you turn
the valve around by hand and give il a
new seat. In a new motor a slap
sometimes develops early and then dis
appears after the first valve grinding.
ID Timing Train
The next most prolific producer of
noise is the engine front end or timing
train. If it is a gear front end it may
be a result of worn gears or tight
gears. The latter produces a howl or
growi depending on the tightness.
Tightness may be a result of out of
alignment due to a bad job of crank
shaft bearing fitting which lifts the
crankshaft gear and brings it to a bad
position. New gears with little back
lash but properly meshed will event
ually wear themselves down to a good
fit, but if gear teeth are running on
the wrong pitch they never will be
quiet, even if they are helical gears.
When the gears are badly worn the
teeth about to mesh hit each other
with some force and if the wear is
great there is a pronounced knock ev-
cry time the engine is accelerated and
accelerated, that is, when you close
the throttle quickly. The latter noise