LightAuto
An insight into the British motoring scene ninety
years ago.
Extracts from the Sixth Edition of the
Autocar Handbook.
Estimated date of publication 1914.
The Light Car.
The feature of the automobile movement which
has attracted most interest during the past few years, has been the development
from the embryo to a very highly finished article of the small car designed
to meet the requirements of those who, aspiring somewhat higher than the
motorcycle and sidecar, are unable to afford either the purchase price
or the running costs of what may be described as the full sized car.
To a very great extent we have to thank experience
gained at Brooklands (Britain's only motor racing circuit at the time)
for the advent and rapid rise to fame of the light car, for without the
knowledge obtained on the track in the direction of securing the uttermost
iota of efficiency from an engine of a given cylinder capacity, we should
never have achieved the success which is ours to-day in light car design
and construction.
A few years ago the man would have been looked
upon askance who advocated the use for ordinary touring work of a chassis
equipped with an engine of which the cubic capacity of the cylinders did
not exceed 1,100 c.c. ; Yet so vast have been the strides made within the
past few years that, not only have some altogether remarkable speed records
been established by small cars with engines below the 1,100 c.c. mark,
but many firms are to-day producing thoroughly sturdy little touring cars
with motors of this size.
We mention the 1,100 c.c. mark for
the simple reason that it has been adopted by the Royal Automobile Club
and the Auto Cycle Union as the Maximum engine size foe a vehicle which
is officially known--for competition purposes--as a cycle car. The great
majority of machines so styled have in reality no resemblance whatever
to motor cycles, and it should be realised that the name "cycle car" is
to be taken rather as a means of indicating the engine size of a light
car than as denoting a special type of vehicle in which motor cycle characteristics
predominate.
As a matter of fact, no definition of a light
car exists beyond the fact that the R.A.C. has so far limited the size
of engines for light cars in trials (A form of motor sport popular at the
time, that included an element of off the road driving) to 1,400c.c. ;
Nor indeed would it be very easy to devise a definition, since there is
between the light car and the large car no great gulf fixed, but merely
a line of demarcation.
While in design the "orthodox" light car
is, to a great extent, a copy in miniature of the large car, there is in
the case of low-powered chassis generally rather more divergence in the
views taken by designers than the case with larger vehicles. This not altogether
to be wondered at, for the light car movement is yet young, and it has
not yet assumed that aspect which is a feature of the world of large motor
vehicles. In this respect the light car and the large car are distinct,
for in the case of the latter the design has become standardised, and save
for comparatively minor points, there is not much to distinguish one from
another. While it would not be accurate to say that the light car has reached
a standard design, there can be no doubt but that it is gradually settling
down to an orthodox pattern which follows the details of the larger cars,
yet there are other types which keep it from being referred to as standardised.
In the first place, there is the light car
designed and built throughout on what may be described as orthodox large
car lines-- that is to say, the light car with a four cylinder engine,
thermosyphon water cooling, high tension magneto ignition, lubrication
by pump and troughs in the base chamber, a leather cone or disc clutch,
a gate-operated gear box giving three forward speeds and a reverse, propeller-shaft
transmission to a bevel or worm-drive live back axle, worm and segment
steering, and pressed steel frame. The determining factor between this
class of vehicle and somewhat less orthodox, but perfectly successful light
car chassis, is not that of engine size, for such small cars as we have
outlined are to be found with engines ranging from below 900 c.c. to whatever
maximum limit it may be decided to adopt.
The we have the light car, of which the engine
has a single or twin cylinders, with water cooling and other features which
have come to be regarded as standard car practice, but of which the transmission
system is of a type found on larger cars. Among light car designers there
are a few who incorporate chain drive to convey the power from sliding
pinion gear boxes to the rear axle, but this form of transmission is not
in very general use. There are one or two examples of light cars in which
friction drive is employed, the drive disc rotating on an extension of
the crank shaft, while the driven disc, which is as a rule, surfaced on
its periphery with compress paper, is designed to slide upon a transverse
shaft, the final drive from the lasted named shaft to the road wheels being
by chain.
Another form of friction-driven light car
is that of which the G.W.K. is typical, in which the position of the engine
enables the final drive to be by propeller-shaft to an orthodox live axle.
It is only fair to mention that it is largely due to the efforts and successes
of the manufacturers of the G.W.K. that friction drive for small cars is
now admitted to be a perfectly practical proposition.
The reference which has been made to the
G.W.K. brings us to the consideration of another point in which divergence
from large car practice is sometimes found. Especially where the manufacturer
has set low first cost as one of the most important ends to be achieved,
we find that a V twin-cylinder engine is sometimes adopted. A few designers
of two-cylinder engines rely upon air-cooling, but the majority incline
to the adoption of water-cooling, even though it entails a little extra
complication and some additional weight. Really admirable examples of the
two-cylinder light car are in existence today, and he would be a bold prophet
who would say that this type of motor is doomed to disappear at an early
date.
Finally we come to a class of light car which
clearly shows that it has been evolved from the motor cycle. Here we find
that the final drive to the rear wheels is by means of two belts. Belt
drive was frequently adopted on the earlier cycle cars; but for one reason
or another it fell into disrepute, and, although there are still one or
two satisfactory belt-driven four-wheelers, the vast majority of small
cars are equipped with transmission by geared propeller-shaft.
In addition to light cars proper, there are
still made a few passenger-carrying three-wheeled machines, which have
survived the test of time and have proved themselves quite capable of competing
with small four-wheeled cars. The two three-wheelers which are most in
evidence at the present are the Morgan and the A.C. ; of these the former
has achieved some remarkable performances on the Brooklands track, and
is a very speedy little vehicle for touring purposes. Whether or not the
three-wheeler will continue to appeal in time to come, when the price of
the four-wheeled light car has been further reduced, remains to be seen;
its lightness and low running cost are in its favour, but, on the other
hand, in comfort, and especially in the space available for luggage carrying,
it cannot compare with the four-wheeler.
Motoring
For the Masses Part two
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