CHANGES IN DESIGN

Timaru Herald, Volume CXXV, Issue 18500, 22 February 1930, Page 10 (Supplement)

CHANGES IN DESIGN

REVIEW OF PAST YEAR. POPULAR ENGINE FEATURES. Looking back over the past twelve months, it is interesting to note the changes in design that have been gradually but surely taking place in the modern average car. During 1929 there has been little of revolutionary character introduced, such as the popularisation of four-wheel brakes four or five years ago, but changes have nevertheless been taking place all the time.

The year 1929 has undoubtedly seen a marked increase in the number of cars fitted with six and eight-cylinder engines, with a corresponding decrease in the number of cars with four-cylin-der power units. Quite a number of new small sixes have also made their appearance, while mention may also be made of the Voisin addition to the double-six class, formerly represented only by Daimler, for it does not appear unlikely that in course of time this type of engine will be used for the largest and most expensive chast designed primarily to give the smoothest and quietest running possible.

% Design of Engines. With regard to details of engine design, it may be said that overhead valves show a slight increase in popularity, and the tendency to increase both the number of cylinders and the crankshaft speed is likely to result in even greater use of overhead valves. It is also owing to the tendency to increase engine speed that greater attention has been paid to lubrication systems, and, while the fully forced system has for some time been standard practice, it is now improved in quite a number of cases by the addition of an oil-cooling radiator. Very closely connected with the engine is the ignition system, and during the past year the magneto has definitely given place to the coil and battery; it may be said that this was foreshadowed in 1928 by the great increase in popularity which the coil system then enjoyed. There has also been a definite increase in the number of engines with pump circulation of the cooling water, and there is undoubtedly a tendency to provide some means of controlling the cooling system by the fitting of a termostat, operating either radiator shutters or a valve in the water path.

Transmission Features. As regards the transmission, features which are increasing in popularity are the unit construction of gear box and engine, the provision of four forward ratios, and the use of an open shaft in place of one enclosed in a tofcque tube. One other very important change in the transmission may be said to have taken place during 1929, that is the introduction of the “silent third.” Strangely enough, it is to America that we really owe this, for as three-speed gear-boxes were universal there, certain manufacturers decided that they could gain an advantage over their rivals by providing their cars with two top gears, hence the expression “twin top.” Gear boxes of this type are slightly different from the normal fourspeed box used on British and Continental cars.

On the whole, there has been surprisingly little change in suspension systems, although several promising designs, most of which incorporate independent wheel springing, have been produced. In some minor, but important details, changes are noticeable, and centralised lubrication systems are becoming more popular both on English and American cars. Also, the need for lubrication of spring shackles and such points is avoided by rubber bushes. In some cases the vacuum feed tank, which has long been the most favoured method of raising fuel from the rear tank, has given place to a fuel pump operated either by the engine itself of by electricity.

A number of developments of tried merit on racing cars and sports models of advanced design do hot seem to have made much headway. Frontwheel drive, for instance, has been adopted by only one British and three American manufacturers.

As regards equipment, quite a number of small changes have been made, and one may cite the increasing number of cars fitted with an anti-dazzle device or dipping headlights. Controls have been rendered neater and are usually carried out in a more workmanlike manner than was previously the case. “Finger-tip control,” as it is called in the United States, for example, is on the increase. In every case, the changes which have been made during the past year make for improved performance or ease of maintenance and each year the task of the owner-driver is being made easier.