Hints for the Motorist

Bay of Plenty Times, Volume LXXI, Issue 13056, 26 January 1943, Page 3

Hints for the Motorist

tg—HSKiaF- X ALBERT L CLOUGH _^^S

WHEN SURFACES ARE BAD HINTS WHICH HELP A volume could be written on the subject of driving on different surfaces. You should always be ready to take advantage of,a dry patch to put in hard braking if you want to slow down. It is incumbent on the driver to so arrange his progress that whenever he passes from certainty to uncertainty the speed finds him ready for it. Hard on Tyres In this connection it should be mentioned that on a really greasy road bad skids can be engendered by a too hasty use of the accelerator. Just as the tyres need a rough-surfaced road to bite on when braking, so it is equally imperative when sudden acceleration is demanded —if wheel spin is not to result. Nothing destroys tyres quite so fast as violent acceleration or braking. Slide Down—Climb Out Really rough roads are dismaying to the motorist, who fears broken springs. There is undoubted risk of damaged suspension if a car is driven carelessly over bad pot-holes. By going slowly and warily, however, the most atrocious surfaces can be negotiated safely. The thing to bear in mind is that a bouncing action, if allowed to persist, will break anything. When a bad depression is in evidence use the foot brakes in such a way, as to let the car slide down into it and climb out. Automatic Control One result of the era of simplication of construction was the provision on a considerable number of makes of cars of a control which governs automatically (or automatically within limits) the advance and retard of the spark. The device generally consists of some form of centrifugal governor which moves the make-and-break. Where the arrangement is called half-automatic it usually means that one or both of the extremes are affected by the hand control while the intermediate range is worked automatically. On some of the big powered and high efficiency cars, and on old models of all kinds, throttle and ignition controls are closely allied in driving and should be worked in conjunction with each other. Many old 'engines fitted with variable spark control are habitually driven with no-regard to the advance or retard lever. Maybe it is left permanently on the low side, when the engine will run unduly hot and without any spirit. Possibly it is always fully advanced, with the result that the life of the car is materially shortened. Spark and Throttle The object to aim at is as much advance with as little throttle as possible. An engine should be driven primarily on the spark and secondarily on the throttle where the advance and retard are not automatically governed. Of course there are limitations to this plan. When once a car is under way, for instance, the speed should be worked up by gradually advancing the spark and easing off the throttle. In this way the good driver will get his speed at minimum cost. The Exception Under a heavy load the process must be reversed, as when climbing a hill. It is surprising how many slopes can be surmounted without a change of gear or undue stress to the engine by skilful manipulation ot the spark lever —gradual movements just when the engine wants them—■ on which otherwise the driver would have to change. For all light work the spark should be kept well forward. Under Light Load The main points to remember are two. When the piston speed is low and the load heavy a relatively late firing point will furnish the maximum power combined with even torque. Under light load the earlier the burning of the charge is begun the greater the speed obtainable. Since the major part of a car's mileage during the year is run with the engine working comparatively light, it follows that full use should be made of the advance permitted on the ignition. If you are endowed with any mechanical sense at all you will readily appreciate why variable ignition is designed and how sympathetic handling of it is conducive to more efficient and economical running.