MOTORING WORLD

Manawatu Standard, Volume LVII, Issue 218, 14 August 1937, Page 15

MOTORING WORLD

FUEL WASTE. CAUSES AND CURES. "When an owner is worried about the excessive fuel consumption of liis car, he is right in concentrating his attention first on the engine. Maladjustment of the carburettor, wrong ignition setting and bad condition of the valves can all, separately or in combination, result in fewer miles per gallon than are obtainable when the car is in proper running order. It must be remembered, however, that there are two other things which can make the petrol disappear at an alarming rate. They are slipshod driving methods on the part of the owner, and an excessive amount of drag in the car’s running rear.

Provided, therefore, that the driver is satisfied that he handles his car in a reasonable manner, accelerating and slowing down in a way that does not involve violent use of the accelerator and the brake, the chassis should be examined to make sure tl\at every rotating part operates with as little drag as possible. This, is an essential part of tuning to improve petrol consumption. OIL DRAG.

A certain amount of friction in the engine and transmission, oil drag in the gearbox and rear axle and tyre drag on the road are unavoidable j these, retarding forces cannot be entirely eliminated, but they may bo kept within reasonable limits by the exercise of a little care. One of the important things is to see that the lubricant used in the various important parts of the transmission is reasonably light. The manufacturers’ instructions regarding the grade to be used should be followed. Do not be tempted into using heavier lubricants, under the mistaken impression that they will do the job better. In most cases they will not, and they will increase the drag in the chassis. This definitely requires extra power to overcome, and consequently, petrol consumption is increased.

BINDING BRAKES

The most frequent cause of exc-essive friction in the running gear is binding brakes. Jack all wheels. off the ground, and revolve each one in _ turn. Jf the brake shoes are binding in any of tile wheels, they will be felt, and heard, .and the setting should be adjusted. Before altering the setting, however, make sure that the trouble is not caused by a seizure of one of the operating cams. If the shalt of a cam is binding in its bearing the shoes on that drum may not be returning to the “off” position. This trouble will involve dismantling the brake concerned, removing the offending cam, and cleaning it and its bearing thoroughly. Sometimes this is all that is necessary, but in bad cases it may be desirable 10 rub the shaft down with emery cloth to reduce its diameter very slightly. Then, if it is replaced, well coated with graphite grease, the trouble should not recur. It is possible, though hardly probable, that excessive friction may be due to. wheel bearings that are too tight. The chances are that the opposite will be the case, and that they will bo too loose because of wear, but if they have recently been tightened for this reason, and the work has been done carelessly, they may be too tight. In any event, while the wheels are jacked up, it is as well to test their bearings on the lookout for both faults. Most motor car wheels are mounted oil tapered roller hearings; indeed as far as the front wheels are concerned, it can be said that all of them are. To adjust for wear, it is only necessary to itui-n the nuts a few threads to bed the rollers deeper into their conical races. Tho nuts must not be tightened too much, otherwise the excessive friction wc are trying to eliminate will result.

PREVENTING WINTER RUST.

All mechanical vehicles arc vulnerable to rusting and the motor-car is no exception. During the winter months especially trouble from this source should be constantly guarded against by the ownei, who believes in keeping bis car in first-class order. In the of ferrous metals, rusting first produces a yellow deposit which is lairly harmless and which can be removed fairly easily—rubbing with brown paper is quite an effective method. Water considerably hastens the rusting process, the colours deepening through orange and brown to a deep sepia as it becomes more advanced. When rusting has set in the only really effective method of removal is to rub it away with an abrasive, such as emery paper, until a clean, bright metal surface is reached. As a preventive against the formation of rust vaseline has an adhesive quality which makes it superior to greae. Paint-like finishes that set hard, flake, or allow corrosion under the finish are of little use and for this reason casual retouching once rusting has set in is not to be encouraged. One method of treating inaccessible rusty fittings is to wash them in petrol and scrub with graphite grease. If the affected parts can be slightly heated beforehand, the pores of the metal are likely to retain the lubricant thus making the treatment even more effective under normal temperatures. Rusting of aluminium alloys produces a chalky film which becomes most evient in the sea air or in moist climates. Rectified, or white, petroleum jelly lias been found most effective in dealing with trouble of this nature, but the most important thing with rust of all types is to prevent it from spreading as soon as it has set in.

FUEL OIL ENGINES FOR CARS

The opinion lias been- expressed by the head of a well-known engineering firm in England associated with the manufacture of motor cars that, although there is considerable doubt about the high-compression Diesel engine ever being adopted for motor oars in any numbers, there a.ppears to be a distinct future for the low-compression fuel oil engine. This type of power unit is practically a combination of the ordinary Diesel and the petrol engine. Injector pumps for the fuel oil arc used, but as the engine has low compression, an ignition system similar to that fitted to cars is employed. No carburetter is needed. Such a power unit running on fuel ,oil instead of petrol would weigh no more than the petrol unit, and its cost would bo almost the sa.me, excepting, perhaps, the injector mechanism. Greater mileage per gallon of fuel would be obtained, while the cost of the fuel would, of course, be very much less. This type of engine has already been used successfully in commercial vehicles, while it is stated that several European manufacturers are turning their attention to the type for car use. 1