Motoring Notes.

King Country Chronicle, Volume XXXI, Issue 4566, 8 November 1937, Page 3

Motoring Notes.

BAD DRIVERS SPOIL GOOD CARS.

Engine wear has been the subject of a good deal of research recently, and it is clear that, although he cannot do much, the driver can do something to reduce it (writes Oliver Stewart in the Morning Post, London). He can do a great deal more with the chassis, and it would not be much of an exaggeration to say that between two extremes of driving, there might be a difference of a hundred per cent, in wear. Let me note some of the precautions that must be used if a car is to be made to last as long as possible. The essential thing about engine wear is that the time taken in warming up shall be cut down to a minimum. It used to be the custom to allow the engine to “tick over” for some time before starting on a cold morning, so as to warm it up gradually. That, it has now been shown, was a bad practice, likely to increase rather than diminish cylinder bore wear.

The present method is to get the engine up to its normal working temperature with the least delay. Some makers fit thermostatic controls, and by-passes in the water cooling circuit to help in accelerating the warmingup process.

Again it seems probable, as a corollary, that it is a mistake, from the engine wear point of view, to set the engine to tick over too slowly. Some people glory in so slow a tickover that one can almost count the cylinder firing, and they go to great lengths to achieve it. But lubrication may siifr-gf by this process—although I k-now of no positive proof that it does., Anyhow the belief among technologists now is that the engine .should not be set to idle at much be--500 r.p.m. VThe methods of reducing wear in pthe transmission are fairly obvious. iViolpxii acceleration must not be inVlubed in, and the gears must be heed sympathetically—and that applies whether they are synchro-mesh, self-changing, or the ordinary type. Especial attention must be paid to clutch work, and the aim must be to insinuate the clutch when starting without previously greatly accelerating the engine.

One of the old-fashioned theories used to be that if the left foot rested on the clutch pedal during free running, it would gradually have the effect of weakening the clutch springs. Those who know what springs can do never beieved in the theory. The real reason why it is bad driving to rest the foot on the clutch pedal is that the foot may ease the spring pressure and cause the clutch to slip slightly when under load. Continual clutch slipping soon calls for a new clutch plate. Much can be done in reducing brake wear. It is possible to drive for thousands of miles wthout ever applying the brakes to the full extent; without ever applying them harshly at all. By' throwing the judgment forward, as it were, so that situations are weighed up well in advance, the amount of braking supplied by the engine will be found to be ample for all but the last few yards, and then only the slightest touch on the brake pedal will be needed.

I think that the decline in the amount the free wheel is used is largely the result of the way most experienced drivers prefer to use the engine as a brake and hardly to touch the ordinary brakes. If the engine is used as a brake, the modern ear with a flexible engine becomes in effect a car with single pedal control. One accelerates by pressing the accelerating pedal and one slows down by taking off the pressure. Under this system of driving the brake linings last for a long time, and if the brake linings last it may be taken for granted that the tyres will last.

Really the system of driving so as to reduce wear of all parts to a minimum may be summed up by saying that it consists in causing the car to move with the greatest possible smoothness at all times. It is never accelerated violently nor braked violently; nor is it ever swung violently round corners. It may not be exactly an inspiring form of driving; but it is restful, and it certainly results in economy of a high order. POWER LOSS. The process of wear is gradual. The engine loses power little by little until suddenly the driver realises that it is not pulling so well—that it does not go up hills with such a verve as it used to, and that more frequent gear changing is needed. Sudden loss of power may also develop, and in either case the remedy can be sought for and probably found from one of the following causes:— Ignition trouble; loss of compression; valves; poor carburation; need for decarbonising.

The causes of overheating are usually air leaks due to sticky valves and bad joints, fan and cooling not working properly, ignition retarded and engine oil shortage, all of which may, owing to the overheating, affect the power output of the engine. These points should be checked. Amplifying the causes of loss of power, the following points should be investigated:— Valves.—Weak springs may not return the valves quickly enough to their seats; after prolonged use the springs may need replacement. Valve clearance incorrect, insufficient causing the valves to remain unseated when the engine is warm, and too much giving insufficient lift to admit a full charge of mixture. These may be of the direct outcome of wear plus lack of attention.

Piston Rings.—lf sticking in their grooves, or, conversely, if loose in worn grooves, will allow gas leakage to occur. One symptom of piston trouble is the emanation of fumes in quantities from the crankcase breather.

Worn Cylinders.—Allowing leakage of gas past the pistons combined with the weakening effect of mixture with air which may enter the combustion chamber in the reverse direction. Cylinder, ring, and valve troubles have serious effects upon the compression, which is reflected in the power output of the engine. Ignition Faults.—May include dirty distributor points; carbon fouling the magneto distributor; dirty plugs or wrong gap (which should be .018 in with magneto and .020 with coil) ; connections loose; short circuiting across coil terminals due to dirt. In the distributor look for sticky rocker arm, broken spring or insufficient spring tension. Exhaust Box.—lt is possible that carbon may have built up in the exhaust system, causing back-pressure. Decarbonise.—lf the engine has not been touched for some time and tends to knock under load. At the same time, regrind the valves, clean ports, and check plug settings.

STEERING TROUBLE. When “backj?sh” develops in the steering gear it is a wise move to inspect the steering connections first before attempting to adjust the steering gearbox itself. In most modern cars these connections are attached by means of adjustable, spring-loaded ball joints, and when a big mileage has been covered it is possible for wear to develop in them, so that a certain amount of slackness becomes evident in the steering wheel by an excessive amount of free movement.

Go over the four ball joints, two on the drag link and two on the tie rod, and carefully tighten by removing the split pin from each one and screwing down the slotted screw in the end of the tubular joint, not as tightly as it will go, but just enough to ensure the spring bearing with some tension on the concave-faced plunger which bears against the ball. Be careful that every split pin is replaced, otherwise one of the ball joints may become adrift, leaving the driver without any steering gear at all.

In certain cars fitted with independent front springing the track rod is divided, and there will be two more ball joints to receive attention. Only when these parts have been dealt with should any attempt be made to adjust the steering gear itself, but it is possible that it will be found that no attention to this unit is needed.

LIFTING JACKS. SIMPLE PRECAUTIONS. DANGERS OF CARELESSNESS. So apparently simple and straightforward a job as jacking up a car in order to remove a punctured tyre can involve the motorist in quite a lot of of trouble and even danger unless he observes some elementary precautions. Cars to-day have a lengthy body overhang and deep streamlined fairings on the mudguards, making it difficult to crawl beneath the car in order to place the.jack in position. Different ideas have had to be evolved for lifting a wheel clear of the ground. While many of these are ingenious, one or two can be horribly unsafe, unless the motorist is careful first to place the car on level ground (a precaution which should be taken in any case, whatever the type of jack used), and is careful about the way he attaches the jack to the car. This applies particularly to the so-called “bumper bar” pack, which is quite efficient and stable when attached properly, but at all times should be viewed with suspicion and treated with respect. On the other hand it is an easy jack to use, and the motorist does not even have to kneel down in order to place it in position. The Vertical Lift. This type of jack consists of a very long threaded steel bar passing through a bracket, which is attached

to the bumper bar support, and on which the car is wound up by a brace fitting into a spindle on the bracket. As the jack lifts the car by the chassis frame the wheel will not clear the ground until the spring leaves have spread wide open, and this involves screwing away until practically the whole of the thread on the steel bar, which may be anything from 21 to 3 feet in height, has been used up. This is one of this jack’s greatest faults. Must Be Vertical. As the car must be lifted to such a height it is necessary that the jack be absolutely vertical while in use. If it is sloping even slightly, some clumsiness* in brushing against a jacjced-up car with the brakes released, may se the car rolling so that the jack folds in under the car, which will then fall heavily on the brake drum if the wheel has been removed—or on top of the motorist if he happens to be crouched under the mudguard struggling with the spare at the time. This point is specially made because one very well known 1936 model, equipped with this type of jack, was provided with permanent brackets for its attachment, but through some miscalculation of the manufacturers, these brackets left the jack standing at a very dangerous angle. Fortunately, the jack, in these cases, can be clipped to the bumper bar support, when it will rest vertically. Other Types. The bumper bar jack is by no means the only type which must be used with care. A good many cars still use jacks which go under the axle, and these must be placed carefully to insure that they fit squarely under the axle beam. Otherwise they will be just as insecure as the bumper bar type, and the owner’s carelessness will involve him in the same danger. This very important matter is coming in for a good deal of attention, and some very good and very safe jacking systems have been evolved, which protect an owner against his own possible carelessness. There are the rather expensive kind permanently affixed to the axles, and operated by screws or hydraulic mechanism, and less costly designs in which special brackets on the car chassis prohibit any damage to car or person arising from careless use. A note of warning may be sounded, in conclusion, regarding the use of a jack for supporting the car for any length of time while work on the undergear is being carried out. Unless the jack is of a particularly stable kind, it should be only used to lift the car to enable blocks of wood or proper wooden horses to be slipped under the axles. DRIVERS AND DRINK. Most sensible people deprecate the suggestion that motorists should not allow a drop of alcohol to pass their lips when they are driving, comments Autocar. On the other hand, no penalty is too harsh for the man who deliberately drives .a car when he is intoxicated. The difficulty, however, is to draw the line between the two. Some folk, it has been said on authity, drive better when they have had a drink; it tends to settle their nerves and to prevent them making mistakes that might arise from an exaggerated attempt to do the right' thing when “all keyed up.”

Light is thrown on the subject by the conclusion of Dr. Ralph Rimmer, chief police surgeon of Bradford, who is reported ot have said that in his experience “alcoholic motorists” in more than 50 per cent, of cases drove more slowly more than usual—probably, added the doctor, “because they knew that all was not well with them.” He summed up the matter by saying that when they came to grief it was more from lack of judgment than recklessness.

Knowing full well the probable consequences if it can be proved that he has been indulging in alcoholic drinks, the average motorist is careful. In the event of any mishap, excitement or nervous reaction can easily be mistaken for alcoholic excess, and in that, most of all, lies the danger to the man who likes to stop occasionally for a “nip.” It is unfortunate that there is, apparently, no easily applied and positive test by which “drunkenness” can be distinguished from “nerves.”