[First
Aquaintance] [Performance]
[Brakes] [Controls]
[Warning Lights] [Clutch]
[Running In]
When
the first post-war Morris Minor was introduced in 1948,
it immediately acquired an enviable reputation as a
small, inexpensive family saloon that possessed the
sensitive steering and beautiful handling qualities
of a thoroughbred sports car. The introduction of an
overhead valve engine in 1952 was a welcome improvement
on the somewhat unenterprising 918cc side-valve engine
fitted to the first models but much of the benefit of
the new power unit was offset, from the enthusiast's
point of view, by the smaller capacity of the engine
(803cc) and the introduction, at the same time, of a
lower-geared rear axle and a gearbox with more widely
spaced ratios. Not until the Minor 1000 was announced
in October, 1956, with a 948cc engine, close-ratio gearbox
and 4.55:1 rear axle, were the full potentialities of
the car realized. Moreover, the new engine had been
the subject of considerable development, including prolonged
high-speed tests on German motor roads, during which
prototypes had averaged over 60 m.p.h. for 25,000 miles.
The Minor 1000, therefore, represents the ideal choice
for many enthusiastic drivers; but sooner or later the
keen owner will probably be tempted to improve its performance
by resorting to a certain amount of tuning and modification,
and its comfort and convenience by a judicious selection
of accessories, as described in Chapters XI and XII.
On
First Acquaintance.
An elementary description of the controls and driving
methods is out of place in a book of this type; driving
instruction these days is very definitely the province
of the expert. Even a fairly experienced driver who
is, however, new to the Minor, may welcome some brief
notes on its handling characteristics, which will aid
in assessing its condition and capabilities. For the
beginner, one or two points concerning the functioning
of some of the controls and instruments will also be
added.
Let
us assume, then, that a well-maintained car is the subject
of a short road test. If the engine is in good mechanical
condition, within a very short distance one becomes
impressed by the fact that this willing, lively power
unit appears to be virtually "unburstable"; an impression
that is borne out by the success of these engines, over
the years, when used in highly-tuned form in competition
and even in small racing cars. At speeds of around 40-50
m.p.h. the engine should be reasonably quiet. As compared
with many other small cars, the Minor is notably free
from road noise and drumming, although some resonance
from the exhaust is noticeable on the overrun. It should
accelerate smoothly in top gear from speeds as low as
10 m.p.h., provided that the throttle pedal is not opened
abruptly, and should pull strongly on any main-road
hill. Second gear will deal with quite steep hills (say,
1 in 7), first gear being looked on more or less as
an emergency ratio — which is as well, perhaps, where
the novice is concerned as there is no synchromesh to
assist the change from second to bottom gear. It is
necessary to double-declutch and to speed the engine
up quite briskly when changing into first with the car
on the move.
Performance
and Fuel Consumption.
The road test should enable a fairly accurate assessment
to be made of the mechanical condition of the car. A
new owner who is doubtful concerning any points should
consult his local Morris dealer, who will, of course,
be thoroughly familiar with the particular model and
the standards to be expected from it. He will be able
to judge, for example, from the liveliness and general
feel of the engine, whether a top-overhaul or other
attention is needed.
As
a general guide, it should be possible, with a saloon
in tip-top condition, carrying the driver and one passenger,
to reach 30 m.p.h. from a standstill, using first and
second gears, in just under 7 seconds, and 50 m.p.h.
in under 20 seconds. This entails, of course, "competition"
driving methods; quite brutal engagement of the clutch
and "snatching" of the gear changes — a treatment which
might, perhaps, be unfair to a well-used car. A less
drastic test is to time the acceleration in top and
third gears. From a steady speed of 10 m.p.h. in top
gear it should be possible to reach 30 m.p.h. in about
15 seconds; from 20-40 m.p.h. takes about 16 seconds,
and from 30-50 m.p.h. a little under 20 seconds. In
third gear, 10-30 m.p.h. should take just under 10 seconds.
It must be emphasized, of course, that these figures
relate to a new or reconditioned engine which has been
properly run-in and which is in a good state of tune.
The acceleration of the Traveller will be a little slower,
owing to the slightly higher weight of this model.
The
maximum speed attainable with a new car is in the neighbourhood
of 75 m.p.h. (say, 85 m.p.h. on the speedometer). In
normal driving 25-35 m.p.h. represents the maximum in
second and 40-60 m.p.h. a usable speed in third, depending
on whether or not one is in a hurry.
Fuel
consumption is always apt to be the subject of controversy
between owners. So much depends on the manner in which
the car is driven and the road conditions that it is
impossible to quote any hard-and-fast figure. For example,
if the car is driven hard by an enthusiast — when it
is quite possible to put nearly 45 miles into the hour
on average give-and-take routes — a consumption little
in excess of 33 m.p.g. can be expected. On the other
hand, with normal quiet driving, using a cruising speed
of about 45 m.p.h., the consumption should be rather
better than 38 m.p.g. Really considerate driving can
return a figure of 45 m.p.g.
Brakes.
The brakes on Minors have always been excellent: if
really effective retardation is not obtained, without
any tendency to pull to one side or to lock one or more
wheels prematurely, the braking system should be overhauled
as described in Chapter VIII. Even on an old car, there
is no reason why the brakes should not be brought up
to modern standards.
Controls
and Instruments.
A few brief notes on the controls and instruments may
help to clear up some of the problems that occasionally
confront the novice. As has already been pointed out,
it is not proposed to discuss in detail any of the actual
driving controls as it would be unwise to encourage
the novice to make his first experiments unaccompanied
by an experienced driver, even when this is permitted
by law.
Choke
Control.
The knob marked "C" controls the position of the carburettor
jet, which is lowered to give the rich mixture required
when starting a cold engine. The term "choke," implying
a form of air-strangler valve, is therefore a misnomer
in this case but has been established by long usage.
The control knob should always be pulled out fully when
starting from cold but should be returned as soon as
the engine will run without misfiring. It can be locked
in any position by rotating it anti- clockwise. If the
mixture control is kept in action unnecessarily, fuel
consumption will be increased and the excessive quantity
of condensed petrol will wash the oil film from the
cylinder walls, causing rapid wear and corrosion.
The
mixture control should not be used when the engine is
hot. It is not unusual, during the summer months, to
see a driver repeatedly using the starter in an attempt
to get a reluctant engine to fire, with the control
pulled out fully. The result is simply to flood the
engine with petrol, creating a mixture which is far
too rich to ignite. In such a case the remedy is to
return the choke control to the off position, hold the
throttle pedal fully depressed and to operate the starter
until the engine fires. This raises a further point:
when starting normally from cold with the choke in use,
the throttle pedal should not be depressed. The engine
should start and idle at a slightly higlier speed than
normal when the mixture control is in use.
Ignition
Warning Light.
The right-hand, lower red warning light fulfils two
useful functions: it glows as a warning to the driver
if the ignition is switched on while the engine is stationary,
thus preventing the risk of the battery being accidentally
discharged and the ignition ceil being overheated. The
warning light is, however, wired into the battery-charging
circuit in such a manner that it glows whenever the
cut-out points are open. Consequently it should be extinguished
whenever the engine is slowly speeded up and the dynamo
develops sufficient voltage to begin to charge the battery.
If the ignition warning light does not go out whenever
the engine is speeded up above idling speed, first make
sure that the dynamo driving belt is not slack or broken
and then have the charging system checked; otherwise
the battery will be quickly exhausted, and (although
a starting handle is provided) it may be necessary to
obtain a tow or professional assistance to get the car
started. It will be seen, therefore, that this little
light is a valuable warning device which should not
be ignored. If the light does not glow whenever the
ignition is first switched on, the bulb should be checked
and renewed as described in Chapter VII or the fault
in the circuit put right at the earliest possible opportunity.
Oil-pressure
Warning Light.
Similarly, the green warning light on the left should
glow whenever the ignition is first switched on. If
it does not do so, the trouble should be investigated
as soon as possible. This light is controlled by an
oil-pressure-operated switch, which is adjusted so that
if the oil pressure falls below a safe figure the light
will glow as a warning to the driver. Obviously this
warning should never be ignored; the car should not
be driven until the oil level in the sump has been checked
and the lubrication system tested by connecting a pressure
gauge to the warning light switch union — a job which
can be done by a Morris dealer or practically any garage.
The pressure shown under normal running conditions should
not fall below about 40 lb/sq.in. About 20 lb/sq.in.
should be recorded when the engine is idling. Low pressure
can be caused by a number of faults, which are dealt
with in Chapter III. If the warning light flickers on
and off when the car is driven fast around corners the
indication is that the oil level in the sump is dangerously
low and that the oil is surging away from the intake
to the oil pump. This obviously is a danger signal which
cannot be ignored. The car should be driven as quietly
as possible until the normal sump oil level can be restored.
The
Clutch.
The clutch on the Minor has a short travel, giving rather
abrupt engagement if the pedal is not released progressively.
If judder should develop, check the adjustment of the
engine tie-rod (Fig. 8) as described in Chapter II.
Some beginners have a habit of driving with the left
foot resting on the clutch pedal. This is a bad practice;
even light pressure, if applied continuously, will cause
unnecessary wear of the clutch release bearing — the
bearing that transfers the thrust from the clutch pedal
to the clutch release levers — leading to noisy operation
and excessive clutch pedal travel. Moderate pressure
on the clutch may cause the linings to slip, resulting
in overheating and rapid wear.
The
same fault will be caused if the clutch is slipped in
an attempt to avoid the necessity of changing to a lower
gear when the engine is overloaded. Wear on the friction
linings will cause the pedal to move further backwards
towards the driver and when the free movement is taken
up, persistent clutch slip will occur. In such circumstances
adjustment to restore free movement, as described in
Chapter II, may not cure the slipping. A clutch overhaul,
which is a moderately expensive item, will be needed.
Running-in
a New Car or Reconditioned Engine.
A new or reconditioned engine, gearbox or rear axle
needs to be "run-in" in order to allow the working parts
to develop a special type of polished surface which
can be obtained only by driving at moderate speeds without
the use of full engine power. It is virtually impossible
for the manufacturer to produce ideal bearing surfaces
by machining procedures alone.
During
the running-in process, however, the minute "hills"
and "valleys" left by the machine tools are gradually
rubbed down. It will be obvious that either excessive
speed or heavy loads on the bearings at this stage can
result in tearing and local fusion of the microscopic
metallic projections instead of a progressive polishing
action. The manufacturers of the car recommend that
the speed in top gear should not exceed 35 m.p.h. for
the first 200 miles; similarly, the speed in third gear
should be restricted to about 25 m.p.h., in second gear
to not more than 15 m.p.h., and in bottom gear to 10
m.p.h. Even when 500 miles have been covered, however,
and the car has received its initial free service, it
should still be treated with respect; it is still very
new and consideration during the first 1,000 miles will
be well repaid by a longer life and sweeter running.
To
be honest, the driving speeds just quoted are given
only as a general guide for the less experienced owner.
Any engineer will tell you that ideal polishing conditions
are obtained only by a combination of moderately high
rubbing speeds and light pressures. While damage can
be done by too high a speed, which causes undue friction
and overheating, excessive pressure at low rubbing speeds
will also cause heavy friction and a tearing action.
One would not attempt to polish household silver by
rubbing heavily and slowly; light, brisk polishing gives
a much finer finish. As much harm can be done by forcing
the engine to labour on a hill at 20 m.p.h. in top gear,
as by driving at 60 m.p.h. when the engine is still
relatively new. The ideal is to maintain, whenever possible,
a small throttle opening. When 500 miles have been covered
the maximum speeds in the various gears can be increased
progressively a little at a time, provided that the
engine is not heavily loaded. It is true to say that
the engine will not be entirely free and will not give
its best performance until between 2,000 and 3,000 miles
have been covered.
Another
aspect of running-in is the necessity for adjustments
to the engine and chassis. It will be evident that during
this initial period the parts will tend to settle down
to some extent and the factory-set clearances will be
altered. Therefore, after the first 500 miles have been
covered, one or two vital points must be checked. On
a new car this will, of course, be done by your Morris
dealer without charge. If a reconditioned engine has
been fitted, however, it may be necessary for the owner
to carry out the work, although most garages prefer
to make the check themselves.
The
contact-breaker points in the distributor will need
to be reset to the correct gap since the fibre heel
of the contact-breaker arm will have worn slightly and
the gap will be reduced. The steel cam which operates
this arm imparts a hard, glazed surface to the heel
which is resistant to wear so that subsequent adjustments
will be required only at much less frequent intervals.
While
dealing with the ignition system it is also necessary
to check the tightness of the sparking plugs, since
air leaks past the washers fitted beneath them can upset
carburation and cause loss of power. The cylinder head
and manifold nuts will need checking and tightening
as described in Chanter III taking care to follow the
sequence illustrated in Fig. 9. Over-tightening can
damage the threads and distort the head or the manifold
flanges.
The
tappet clearances will then require adjustment. The
slow-running adjustments on the carburettor should be
set as described in Chapter V. A rather weaker slow-running
mixture can be used when the initial stiffness of the
engine has worn off. The friction linings in the clutch
and brakes will have bedded-down so that it will be
necessary to carry out adjustments to both these items,
as described in Chapters II and VIII.
Also,
the wheel nuts and the castellated nuts on the rear
axle shafts may have bedded-down and should be checked
for tightness; this is a safety precaution that should
not need stressing. Under-chassis items should be checked-over
while the car is on a lift. Finally, the car should
be taken on the road and the engine thoroughly warmed
up, after which the oil should be drained out, carrying
with it any particles of metal that may have been rubbed
away from the new parts.
Running-in
Compounds.
It is worth mentioning at this point that the use of
one of the various proprietary types of running-in compound
is an advantage when running in a new or overhauled
engine. These compounds contain colloidal graphite or
molybdenum disulphide in extremely finely divided form
which adheres to the surfaces of the mating parts, forming
virtually a chemical bond with them. The action of graphite
or "moly" can best be understood by considering the
surfaces as they would appear under a microscope. With
normal running-in, the minute peaks and valleys are
gradually rubbed down until reasonably flat surfaces
are obtained. When a running-in compound is added to
the oil, however, it is deposited in small flakes or
scales, forming a slippery skin which is bonded to the
metal and is capable of lubricating a bearing even when
oil is not present. It also facilitates the spreading
of an oil film.
It
will be evident, therefore, that a bearing is not run-in
by the usual rubbing down process; the metal is not
abraded away. Instead a most interesting process takes
place which the metallurgist terms "plastic deformation."
The peaks and valleys are levelled out by actual deformation
of the metal and a surface layer is formed which is
extremely resistant to wear. After the initial running-in
period a running-in compound still confers some benefits
although its use is by no means essential. In the opinion
of the author it is an advantage always to use a small
proportion of graphite or molybdenum disulphide — say
one-fourth of that recommended for running-in purposes
— in order to maintain a protective film on the working
parts. One other point should be borne in mind; because
of the less drastic action which takes place during
running-in when one of these compounds is used, the
running-in period may be rather more prolonged than
would otherwise be the case. It is as well, therefore,
not to over-stress the engine for, say, the first 1,000
miles and to treat it with respect even after this mileage.
The result will be an engine which will have a much
longer life between overhauls and one which will probably
delight the eye of the expert when it is eventually
stripped for examination.
Of
course any companies or products mentioned in the text
may not exist today and any prices listed are of course
no longer valid, so take company and product refernces
with a grain of salt.