Richmond times-dispatch. [volume] (Richmond, Va.) 1914-current, 1920-06-06
.S|MPL|F|ED LESSONS IN
CARE OF AUTOMOBILE
Loss OF Compression and Its Dis
covered Discussed by Engineer
Gucrrlich.
BY FREDERICK c. GUERRLICH, VI. Il.

r By FREDERICK &. GUERRLICH, VI. +.
Lecture No. 100.
81 Let us now see how the first of the
S4thrcc essentials. namely loss of COM
preston. can go wrong,
q The illustration shows the various
places through which the compressed
gas might escape The spark plug
5 may leak at y. the nut which holds
the. porcelain into the metal part, this
s leakage generally being accompanied
by Kissing sound. The remedy for
this is TO tighten the nut. and this
falling TO remedy the trouble. it
would probably be wise to replace
the plug.
There may DO leakage between the
s. plug and the cylinder or valve cap.
at the place where the plug is
screwed in. as Il. The remedy is to
screw the plug in farther. or il may
be nccessar yio put new gasket
CHAT is, packing washer under IL.
Leakage here may be discovered by
pouring little oil around the plug.
and the amount OF leakage can he
judged by the degree OF bubbiing
when replacing spark plug 1t is a
good practice to make paste of
some flake graphite and lnSeed OF!
\ Cor. II you have no linsecd oil, cylin-
der Old, and TO smear this on the
threads of the plug. This VIII not
only help TO make the plug tight.
metal of the cylinder from fusing to-
gether. due TO the heat, SO that the
plug cannot be taken out again.
The compression cocks may also
leak. This may be at the threads.
as with the spark plug at the valve.
or the stem may be broken. especially
II ii be one OF the long-stem type.
The test for leakage is the oil AS
given for the plug. ! might say that
the stems OF the compression cocks
do often break and cause grca;
leakage. and yet tho stem vii! look
perfect to the eye.
Where LcnkaEc Occurs.
Leakage may, and very often does.
cEcur at the n..lvc caps, c. oil
! whether there is leakage at this
/ place. When the valve caps are re-
placed. after grinding the valves. new
Easkets should always be used.
J shcllac and fake graphite on the
threads will do a great deal to make
them tight. | do not recommend the
using OF the shellac and graphite on
! liable 10 make the unscrcwinS of the
plugs difficult, and should the plugs
hold tighter in the valve cap than
the valve caps hold in the cylinder.
plug without taking the cap also.
SO that the replacing OF defective
plug may prove a difficult task.
The next place to look for leakage
is at p. the valve. There are a num-
Der OF things which might be the
cause OF leakage here: namely. the
waves may nave become burned, or
as it is termed. pit;ed. and so need
reGrindinE; the valve head may have
warped: the valve stem may have
stuck IN III, guide the valve, spring
may have broken or the adjusting
nuts, T.. may be too high. so that the
valve is not seating property. Your
judgment Will tell YOU whether or
not the valves need to be rcg!ouni,
as this should be done about every
1000 miles, and the fact that they
need the reEr;ndinE Will be indicated
to YOU by the gradual loss OF power.
The fact that the valve head has
warped tunusua! in the later model
icars), can only be determined by tax
ing the valves out. You Will be able
to see the broken spring, or sticking
valves, and YOU can tell il the ADJUST
ing nuts axe too high by feeling OF
of about the thickness OF piece OF
paper, and, By raising the nut with
your fingers, you should be able TO
feel this clearance.
II Will pay IL the saving Of raso-
line, 10 have your valve ground in"
quite often, as loss o: power which
VIII result from loss OF compression
means that YOU are not getting al! OF
the power OUT Of your fuel.
: The next place where leakage is
liable 10 occur IS al l., the piston
rings. This may be due To "A broken
ring. worn rings. the rings sticking
ting between them and their grooves
scored-that is. scratched-cylin-
der. due to the engine becoming over
heated FOR lacI; OF Of! or water. or 10
the slots OF the rings getting i'm lin.
Mnen tne l.StONS are pIt into tn.