El Paso herald. (El Paso, Tex.) 1901-1931, 1913-06-07

knock is eliminated. Please let me
know what might cause this knock
Alfred Oliver.
Motor knocks may arise from many
causes. Tightening the bearings will
not eliminate them without more
definite information IL is impossible
TO guide you. From what you state
IL would appear that your trouble is
slight. 1t may be that the timing
gears are considerably worn and the
knock you hear is due to the back lash.
When the motor IS running fast, of
course, this would not be noticed so
much. 1t may also be due to- a side
slap Of one Of the valve push rods.
Such knocks as this are aggravated
motor is idhng- Then, again. the
knock may be caused by the spark be-
ing too far advanced.
X
Motoring department, The Herald
The compression Of my motor has fall
en- off since had the valves on my
car ground. How can get my car to
develop its full power again, and what
is the cause Of my present trOuble2-
R D. H
As the valves are ground to their
seats, they naturally set lower. 1t is
possible that there is not sufficient
clearance at the end of the valve
stems, or that the upper end of the
valve lfters-the push rod adjusting
nuts-are worn. irregularly. If the
adjustment is close at this point, a
should be sufficient to partially IN
seat the valves If the valves are prop
erly ground, and adjusted there could
be no leaks at these points, and it
is possible that the compression leaks
are elsewhere Compression leaks
through the valves may result any
time slight piece of dislOdged car
bon will unseaC a valve This may
happen after a motor has been thor
Oughly OverhaUled. This especially is
applicable to the exhaust valves, since
all the combustion residue must pass
over them
Motoring department, The Herald
In timing the valves on motor, what
is the amount before and after top
and bottom center; is it proper to mesh
the timing gears, also what is the
amount Of clearance to allow between
the valve stems and push rods?-W-
Walz.
Motors Of different design differ as
to the valve setting. The valves Of
a high speed motor must have more
lead than those Of a slow speed motor
There is no fixed rule to apply to all
engines whereby they viii develop
age four cycle motor, the following
valve setting applies: The exhaust
valve should open approximately As
degrees before bottom center and close
approximately 10 degrees past top cen
ter The intake valve should open ap-
proNimately Il degrees past top center
and close apprOElma tely so degrees
past bottom center. The clearance be-
tween valve stems and push rods dif-
ters with motors On the average IT.
head motor the clearance usually al
lowed is about 1-64 inch. or sufficient
space TO allow for expansion and con
traction. On certain T. type motors
this rule cannot be followed It is
always best 10 allow as little clear
ance as possible in order to permit as
much valve lift as possible Certain
motors however, VIII not permit Of
this close adjustment. Each push rod
however, should be equally adjusted so
that the lift Of each valve viii be uni
form
Motoring department. The Herald
Ny car has a disc clutch When il
is released q scraping sound comes
from the clutch case, and when IL is
engaged il slips. I have tried to elm
mate the trouble in several ways with
out result What would you advise2-
X n. Aarons
Would suggest that the clutch should
be thoroughly cleaned with kerosene.
Two OF three quarts should be used,
at the same time letting the motor
run in order to thoroughly penetrate
all the clutch parts. Engage and dis
engage the clutch while motor is run
ming. The clutch case should be
drained and the same operation re-
peated until parts are clean After
this use a mixture OF light cylinder
oil and kerosene in proportion about
three to one II the clutch does not
hold use more kerosene If too fierce
use more oil. Note the proportions
that you can without trouble repeat
the above about every 500 or 500 miles
x
Editors Note-We have received sew