The Maui news. [volume] (Wailuku, Maui, H.I.) 1900-current, 1921-03-25

dTu Ol DTd1CutS Ill lHe ttllltOig odlu
in a recent conversation with a repre-.
sentative of this paper: "Lubricating
systems of automotive engines are al
most universally of the circulating
type. The amount of oil pumped al
ways exceeds the actual amount re-
uuired by the bearing surfaces for
fabrication, the surplus flowing back
to the main reservoir to be again cir
culated by the pump; thus it is ap-
parent hat the entire oil supply is
uniformly affected by any deteriorat-
ing i%nfluencse arising from engine
operation, and hat any foreign mat
ter present is mixed with the entire
body of oil. Oil deterioration result
ing from engine operation is caused
by:
81. Fuel passing the pistons.
80. Carbon.
"3. Road dust.
"a. Water in ~crankcase.
"5. Metallic particles.
Fuel Passing the Pistons
of fuel should be poured into the
crankcase of an engine by mistake, the
operator would insist that it be drain
ed and fresh oil put in because the
lubricating value of the oil would
have been seriously impaired. Yet to
a certain extent this dilution is going
on continually during ordinary engine
operation.
THE fuel is mixed with air and con-
verted into a vapor by the carburetor
but some heat must be supplied to
the mixture to prevent condensation
before it reaches the combustion cham
Der. The heat supplied to the charge
is not always sufficient, with the re-
suit hat at times more or less OF the
fuel is in a liquid state when 1t
reaches the cylinders. Also, the
engine is cold, a portion of the Vapor-
lied fuel will condense upon the sur
face of the combustion chamber.
Fuel can not get into the lower
crankcase except by escaping past the
pistons. If admitted into the cylind-
ers in LIQUID form more or less OF II
will get by the pistons.
Leakage, between the piston ana
cylinder walls during compression and
power strokes, allows a small amount
of fuel to pass down into n lubricat-
ing oil in the ~crankcase. The amount
of fuel mixed with the lubricating OIL
i IN this manner is dependent upon the
mechanical condition of the englne,
the skill and care of the operator, the
kind and quality of the l~ubricating Oil,
the fuel used, and conditions OF opera
ton.
If the cylinders and pistons are out
of round, scored OF too loose IN the
cylinders, this leakage will be increas-
ed. Piston rings should bear evenly
against the cylinder wall and the gap
between the ends of each ring shouid
be no greater than necessary TO allow
for expansion without binding. Inc
rings should also fit properly in the
grooves in the pistons.
Maintenance of the piston seal is
also dependent upon he quallty ano
condition of the ~lubricating Oil III
use, which must be of the correct pody
to fit the requirements of the engine
to be fabricated, and which must nov
he allowed to become excessively thin
from fuel dilution.
Proper operation is important, as
much can be lone to reduce crank
case ailution in starting n driving
the Automobile or truck.
1.-THE lubricating system of the en-
CINE should always function as intend.
ed so that oil in proper quantities VIII
be deposited on the cylinder walls
Improper manipulation OF the car,
buretor choke or printing device VIII
cause excessive crankcase dllutlon by
supplying a surplus of liquid fuel
some of which will get by the plstons
into the crankcase. Until the engine
has warmed up sufficiently it may be
necessary to use the choker, but II
should be controlled sc as not to per,
nit more than the necessary amount
of fue! to be drawn into b engine
"Where the use of the engine is in.
termittent, with frequent starting ano
stopping, imperfect vaporlzatlon ano
excessive fuel condensation IN tne
combustion chambers are to
occur because the engine does not De
come sufficiently warmed.
"The throttles on most carburetors
are adjusted so that in the closed
position. a small opening remains
sufficient to keep the engine running
slowly. When going down Ions
grades drivers frequently shut on the
ignition. using the engine as a brake
Engine temperature is thus rapldl!
lowered while fuel continues to DC
drawn into the combustion chambers
This fuel is not burned but condenses
as the engine cools off and escapes
mast the p~istons, washing the lubricat
ing oil film from the cylinder walls
and passes to the crahKcase' iur'he'
diluting the oil supply.
"Fuel condensation in the compus
tion chamber will also be increased
when the carburetor delivers a mix
ture which is too rich.
Carbon
"The center of the piston, being ex
nosed to the heat of combustion
reaches an extremely high tempera
ture. A portion of the oil thrown VI
bv the revolving cranks strikes thu
underside of the piston head, In TIM
a deposit of carbon or charred oil WI
be formed on this hot SURFACE, SON th'
r~eciprocating motion of the piston
and mixed with the crankcase OF
Fuel carbon, formed in the combustlo
chambers and back of the upper PTS
TON rings, works down past the pts
tons into the oil. This is particular
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