Toyota B User Manual

LUBRICATION
SYSTEM
-
Description
LU-3
IY
l
I
I
I
I
I
A
pressure
feeding
lubrication
system is used
to
supply
oil to
the moving
parts
of this
engine. The
lubrication
system
consists
of an
oil
pan,
oil
pump,
oil
filter
and
oil cooler,
etc. The
oil circuit
is
shown
in
the illustration
at the
top
of the
previous
page.
Oil
from
the
oil
pan
is
pumped
up by
the oil
pump.
After it
passes
through
the
oil
filter,
it is
cooled
by
the oil
cooler and fed
through
the oil holes
in
the
crankshaft
and
cylinder
block.
After
passing
through
each
part
and
performing
its
lubricating
and
cooling function,
the oil is returned
by
gravity
to
the
oil
pan.
A dipstick
on
the side
of the
cylinder
block
is
provided
to
check
the oil level.
OIL
PUMP
The
oil
pump
pumps
up
oil
from
the
oil
pan
and
sends it
under
pressure
to each
part
of the engine.
An
oil
strainer is
mounted
at
the inlet
to the
oil
pump
to remove
impurities.
The
oil
pump
itself
is
a
trochoid
type
pump,
inside
of which
is
a drive rotor
and a driven
rotor.
When
the drive
rotor
rotates,
the driven rotor
rotates
in
the same
direction,
and
since the
axis
of the drive rotor
shaft is different
from
the
center
of the driven
rotor,
the
space
between
the two rotors
changes
as they rotate.
Oil
is
drawn in
when
the
space is wide
and is
discharged
when
the
space is narrow.
OIL PUMP
RELIEF
VALVE
A
relief
valve is
installed
on the
oil
pump
to
prevent
a
sudden increase
in
hydraulic
pressure
when
the
engine is
started at
a
low
engine
temperature.
When
the hydraulic
pressure
is
7 kg/cm2
(99.6
psi,
686.5
kPa)
or less,
the relief
valve
is kept
closed
by the
coil
spring, but when
the
hydraulic
pressure
exceeds
7 kg/cmz
(99.6
psi,
686.5 kPa),
it
overcomes
the force
the
spring,
the
valve
opens and
the oil
passes
along
the
relief
passage
to return
to the
oil
pan.
OIL FILTER
There
are
two types
of oil filter,
a full flow
type
and
a twin
element
type with
a
bypass
system.
Both
types
of filter
have
a
paper
filter
element
with
a
built-in relief
valve.
Particles
of
metal
from
wear,
airborn
dirt,
carbon
and
other impurities
can
get
in
the oil during
use and
could cause
ac-
celerated
wear
or siezing if
allowed
to circulate
through
the
engine. The
oil filter,
integrated
into
the oil line,
removes
these impurities
as
the
oil
passes
through
it. The
filter is
mounted
outside the
engine
to simplify
replacement
of the filter
ele-
ment.
A relief
valve
is also included
before
the
filter
element
to
relieve
high
oil
pressure
in
case the filter
element
becomes
clogged with
impurities.
The
relief
valve
opens when
the oil
pressure
over-
powers
the force
of the
spring.
Oil
passing
through
the relief
valve
bypasses
the
oil
filter
and flows
directly
into
the main
oil
hole
in
the engine.
J

Toyota B Specifications

General

Brand	Toyota
Model	B
Category	Engine
Language	English