Tulsa daily world. [volume] (Tulsa, Indian Territory [Okla.]) 1905-1919, 1917-12-02

inc, grinding or growing, and squeak
ing.
The Kissing will generally indicate
that either the exhaust manifold Is
loose or cracked, allowing the eN-
haust gases TO escape at T. or Il of the
illustration; that these gases are es-
Gaping between valve stem and guide
ut W, or that there Ia leakage Of the
exploding gases This leakage might
be at the spark-plug, either thru the
plug itself as at A. or past the threads
and gasket AA. Tightening or replac
ing is the remedy The leakage may
be at the compression n-cock, either
past the threads B or thru the valve
at BIB The stem may also be broken
at u. Then again the leakage may be
past the threads and gasket of the
valve caps, as at C, past the valve, or
the piston rings. The latter leakage
may be due 10 the rings having lost
their elasticity, To being broken, worn
or scratched (scored) to having the
slots In line or to carbon getting in the
grooves. As the air enters the auNil-
iary valve OF the carbureter there will
also be a hiss, but this is quickly rec
ogniZed, the same being true of the
hiss due to n stcaming radiator.
With the exception of the hiss due
TO the exhaust manifold, valve stem
and carhuretor, n hiss is generally
sign of loss of compression and there
fore loss of power.
The dun pounding noise is generally
an indication that the mixture is too
rich; that the spark IS too far ad-
Nanccd; that there is over heating: or
that there is carbon i'm the cylinder
or on the piston head as at IL, or
valve head G. While the engine Will
not give its best service If 1t has any
one of these faults, II may be almost
ruined because of the oVcrheating. 1t
would be well, therefore, to determine
the cause of n dun pounding noise
which can readily be done by pro-
cess of elimination.
The knock is generally sound
which should be regarded as a dan
ger signal. as II Is generally a sign
that some part, subject to the fun
force of the explosions is loose. Fail
ure To locate II may result I'm an eX-
pensiNo breakdown.
A knock may be due to a worn or
broken wrist-pin bushing | worn or
broken connecting rod bearing j;
loose connecting rod cap. *, worn or
broken main bearing l.. or Loose main
bearing cap NJ, Also TO loose half
time gear or fly-wheel: to play In
the grooves OF the discs OF n disc
clutch, or to loose cylinder blocks. OF
course there can he muumerahle
other ways, such as nuts or even tools
being left in the engine when repairs
are made, or using a long bodied
spark plug, when a short should be
used, thus having the plug hit by the
valve head,
while many stunts" and devices
are constantly being given to locate
knocks, IL is the writer's opinion that
the novice should let an experienced
RlNNN Il.
thru the metal of an engine and seem
60 come from an altogether different
spot than IL actually does. and SO n
really dangerous knock may be con-
sidered harmless. knock is a sign
of danger TO the engine.
Like the knock the tap and click
is generally n sign OF "A loose or worn
part, but the part is generally one
which Is not under so great load,
and will most often come from some
portion Of the valve mechanism. Prob
ably 90 per cent of the taps are due
10 the valve adjusting nuts not being
properly set, so that there is a space
between the valve stem and nut, at
i. The clearance here should be about
that of the thickness of piece of ma
Mia wrapping paper. The tap may
also be due TO the surfaces at Il be-
ing worn at an angle, causing a side
sap OF lHe waive stem against It's
guide at w, or of the push rod AGAINST
its guide at " 10 a broken spring O;
to worn roller @; to chlpped cam II;
10 worn cam shaft bearings; to worn
half-time gear key s; TO a slapping
chain u; 20 loose or broken piston
rings u; or to piston slap, which is
caused by a worn piston and cylinder.
The piston slap will give from u slight
tapping sound TO n distinct knock
As rule n tap Is not dangerous
but IL indicates looseness, and should
therefore be looked TO.
When there are gears. there will al
ways be certain amount of hum
ming or growing noise. Thus in an
engine a growl will usually come from
the half-time, magnetic or generator
drive gears al r. When IL does not
come from q gear, IL will come from