Tulsa daily world. [volume] (Tulsa, Indian Territory [Okla.]) 1905-1919, 1916-04-23
brication. apply to both Of these sys-

brication. apply to both Of these sys-
TENS.
In the splash system on four-cycle
motors the reserve oil IL contained
in the crankcase and each cylinder
Is fabricated by the splash OF its own
crank A dipper on the end OF the
connecting rod dips into trough or
oil when the crank Is at It's lowest
point. and with the upward stroke ni
the crank throws the adhering OIL
violently against the cylinder walls
The oil then is spread evenly on the
cylinder walls by the piston as 1t slides
up and down. The operation In a
four-cylinder motor then Is as fol-
lows:
Suction stroke.
on the previous up-stroke Of the
piston oil was spread on the cylnder
walls and this furnishes fabrication
as the piston descends on the suction
stroke. Al the bottom of the stroke
the connecting rod dips in the oil.
Compression stroke.
The film that has just lubricated
the piston on the suction stroke VIII
I not be affected by the cool gases en-,
terlng from the carbureter and VIII
be left intact to lubrcate on the COM
preston stroke. As the piston goes
upward il smears "A fresh film on the
walls A new, supply Of oil also is
splashed on the lower part OF the cyl
indor by the upward throw Of the
crank
Explosion strokes.
The film smearod on the walls on
the compression stroke also is suftl-
cieut to mbricate the piston on thc
down stroke. The combustion space
on this stroke is exposed TO very
high temperature, but the flame only
comes in contact with the oil film
after il has performed its purpose
of lubricating the piston. AT the bot
tom of the stroke the rod again dips
in the Oil
Exhaust stroke.
This is the stroke in which the most
difficulty ig encountered with the lu-
brication. The oil film on the upper
part of the cylinder walls mas just
been exposed to very high tempera-
ture and certainly has been damaged.
1t still possesses degree of lubricat-
| ing value, however. and the piston
itself now is covered with "A film OF
oil as il moves upward. The combi-
nation of these two should he suffi-
cient for the fabrication of this stroke.
| If trouble is encountered due to faulty
| fabrication, however, II VIII snow
principally on this stroke.
Three essential requirements of
good motor-cylindcr oil are:
First-It must lubricate at the tenn
perature encountered in the cylinder:
Second-lt must give good seal
to the piston and rings p'eventins
leakage of gases and oil past them.
Third-It must burn without form
ing carbon deposits in the cylinder
| when oil gets into the combustion
chamber.
The lubricating value of an oil is
due to the fact that when the surfaces
OF the cylinder and piston are separ-
ated by film Of oil the friction OF
these two metal surfaces Is eliminated
and the fritcion remaining is only
| that of the oil molecules sliding past
each other.
The quality of an oil that gives
| the comparative measure of the fric-
| ton generated is the viscosty, and
| this may be defined as its resistance
| to flow Oil manufacturers generally
express it numerically compared to
| that of water taken as unity. The
| consumer expresses 1t roughly as
| light. medium and heavy. terms that
are generally understood. The higher
| the viscosity the less fluid the oil,
| and the greater the liquid friction.
The viscosity of an oil decreases
| greatly with an increase of tempera-
ture.
| The deciding factor with regard to
viscosity is the condition of the piston
and rings. If these are tight. light
oil will be satisfactory. A heavy oil
| becomes necessary if they are worn
and loose. If the oil is too light it
will be drawn past the rings on the
suction stroke and on the compression
stroke some of the gaseous mixture
will leak past and tend to make the
oil in the crankcase still lighter. Un-
! der the conditions of high rubbing
speed and small piston-ring pressure
| that now are generally found light
oils should give the most efficient
results in the majority of cases.
Before discussing the effect of high
| temperatures, it will be well to deter
mine just what they are. Recent eX-