MG MGB User Manual

THE
ENGINE
A
GENERAL
DESCRIPTION
The
overhead-valve engine
is
built
in
unit
construction,
with
single-plate
dry
clutch.
Cylinder bores
are an
integral
part
of
the
block
and
are
water-jacketed their
full
length.
The
valves
are
set
vertically
in
the
detachable
cylinder
head and
are
operated
through the
medium
of the
rocker
gear,
push-rods,
and
tappets
from the
camshaft
in
the
left-hand
side
of the
cylinder
block.
Renewable,
thinwall bearings
support
the
counterbalanced
crankshaft, while
end-thrust
is
taken
by
the
thrust
washers
■tted
to
the
centre
main
bearing.
The
camshaft is-driven
by
a
duplex
roller chain
which
is
automatically
adjusted by
a
spring-hydraulic-operated rubber
slipper.
The
oil
pump,
distributor,
and
engine
revolution
indicator
are
driven
from
the
camshaft;
each
component
has
its
own
drive
shaft.
Section
A.1
OIL
PRESSURE
Under
normal running
conditions
the oil
pressure
should
not
drop
below 50
lb./sq.
in.
(3.5
kg./cm.2)
on
the
gauge
at
normal
road
speeds,
whilst
approximately
15
lb./
sq.
in.
(1.05
kg./cm.2)
should be
shown
when the engine is
idling.
New engines
with
new
oil
will
give
considerably
higher
readings
at
low
speeds.
Should
there be
a
noticeable drop
in
pressure,
the following
points
should be
checked:
1.
That
there
is
a
good
supply
of the
correct
grade
of oil
in
the
engine
sump.
2.
That
the
strainer
in
the
sump
is
clean and
not
choked
with sludge.
3.
That
the bearings,
to
which
oil
is
fed
under
pressure,
have
the
correct
working
clearances.
Should
the
bearings
be
worn
and
the
clearances excessive,
the
oil
will
escape
more
readily
from
the
sides
of
the
bearings,
particularly
when
the
oil
is
warm
and
becomes
more
■uid. This
will
cause
a
drop in
pressure
on
the
gauge as
compared
with that
shown
when
the
bearings
are
in
good order.
M0880
Later
type
filter
(disposable
cartridge)
1.
Filter
cartridge.
2.
Filter
head.
3.
Seal.
80619
MGB.
Issue
7.
Section
A.2
LUBRICATION
Checking
the engine
oil
level
Inspect
the oil
level
in
the
engine
and
top
up
if
necessary
to
the
‘MAX’
mark
on
the
dipstick.
The oil ■ller
cap
is
on
the
top
of the
engine
valve
cover
and
is
released by
turning
it
anti-clockwise.
Changing
the engine
oil
Drain
the oil
from
the
engine
by removing
the
drain plug
on
the
right-hand
side
of the
engine
sump.
The
oil will
■ow
more
readily
if drained
when
the
engine is
hot; allow
at
least 10 minutes
for draining
before
replacing
the plug.
NOTE.wDisconnect
the
battery
cable
from
its
terminal
on
the
starter
before starting
work
on
the filter.
Engine
oil filter
The
external oil
filter
is
of the
disposable
cartridge
type
and
is
located
on
the
right-hand
side
of the
engine.
Early
cars
are
■tted with
the
renewable element
type
of ■lter.
To
change the
filter
cartridge. Unscrew
the
01d
■lter
cartridge
from the
filter
head and
discard. Smear
the seal
of
the
new
filter
cartridge
with oil,
locate
on
the
■lter head
and
tighten
with the
hands
only. DO
NOT
USE A
SPANNER
T0
TIGHTEN.
NOT
OVERTIGHTEN.
To
renew
the
filter element,
drain
the
■lter
by removing
the
plug;
unscrew
the ■lter
body
securing
bolt
and
lift off the
body.
Wash
out
the
casing
with gasoline
(fuel) and
dry
it
before ■tting
a
new
element.
Check
that
the sealing
rings
and the rubber
washer
are
in
a
satisfactory
condition.
Reassemble
the
■lter, ensuring
that
the
components
are
correctly
positioned.
Early
type
filter
(renewable
element)
3.
Sealingring.
4. Rubber
washer.
5.
Sealingring.
1.
Drain
plug.
2.
Bolt.
A.3

MG MGB Specifications

General

Brand	MG
Model	MGB
Category	Automobile
Language	English