THE MOTORIST

Northern Advocate, 17 December 1932, Page 15

THE MOTORIST

When assembling, be very careful that the gaskets are properly fitted and in good condition, and that pipe unions are sound and tight. Also drain the sump on the bottom of the main fuel tank, to remove any sediment that has collected there, and might ultimately roach the vacuum tank or choke the main pipe.

One of the commonest little worries besetting the uninitiated motorist is the cracking noises which come from under the car after a run- when the car is cooling off. Nothing is going wrong; in fact, the cracking must inevitably occur. It is caused purely and simply by the hot exhaust contracting in the process of cooling.

GRAPHITE LUBRICATION,

ASSEMBLING HINTS.

A COMMON WORRY.

FOCUSSING HEADLIGHTS

THE ART OF DRIVING.

USE IN ENGINE AND TRANSMISSION.

The value of graphite as an ingredient in engine and transmission lubricants and its alleged disadvantages have long been controversial matters among ear engineers. Although at one time there was a belief that graphite compounds were ideal lubricants, popular opinion has now swung in a contrary direction, and there is a definite piejudice against the adding of any adjuvant to the many excellent lubricating oils which are now sold. “When doctors disagree’ ’ it would be presumptuous to dogmatise, but there is much evidence- to support the claim that colloidal graphite has many valuable properties as a lubricant when combined with the engine oil or the transmission lubricants of the modern

The following notes have been compiled in collaboration with Mr -I. Eleldcr, the chief technical engineer of the N.R.M.A., who has carried out a number of enlightening experiments. It is necessary to draw a clear line of distinction between the ordinary graphite, which is used cither in flake form or mixed with grease for the lubrication of certain working parts, such as road springs, which do not require a very fluid lubricant, and the colloidal substance, wdiich combines readily with ordinary oils.

The latter during the processes of manufacture us treated at a temperature of about 7000 degrees F., so that all traces of foreign matter »are destroyed, That fact contradicts one of the allegations against the substance —that it wall not stand up against the temperatures of the combustion chamber, which in the case of the petrol engine are nprmally below 2000 degrees F. : Those who champion graphite state that when a small quantity of the colloidal product is introduced into the engine it rapidly provides a filling for the microscopic pores of rlie metal of the frictional surfaces, and so ensures a polish on the wearing parts which no amount of careful runningin could give. It is also said that the graphite tends to build up at points -where there is an excessive clearance, and in regard to that; claim it is necessary to consider the opinions of two expert critics, one a university professor, the other Mr Fielder. The former has stated that a potential objection to the use of colloidal graphite in the lubricating oil of the engine is that it might, because of its alleged property of accumulating at frictional parts, ultimately constrict the flow r of lubricant to pressure-fed bearings. On that point reference must be made to certain laboratory tests which were carried out at the British Physical Laboratory, •

Temperature Tests

Temperature recording devices were fitted to the bearings of an internal combustion etlglno, whose oil reservoir was first filled with ordinary lubricant in which there was no graphite. While the engine was running the sump was drained, and it wae found that within 35 minutes the temperature at. the bearings had risen to danger point. Subsequently a similar test was made after the engine had been charged with graphite-impregnat-ed oil, and it was found possible to run it for 26$ hours bcfdKje the temperature at the bearings became excessive.

It is contended that within desirable limits a “graphited” lubricant lends to build up bearing clearance, but it is also claimed that no harm can result from that process, for the graphite itself is an excellent lubricant, and while it is present the calls upon the oil are minimised. It is said, too, that the margin •of clearance in the working parts of any car which has been run-in far exceeds the tak-ing-up which might result from the presence of a graphite film. Conversely, it has been found that where excessive play exists the mixing of a proportion of colloidal graphite witli the lubricant may be beneficial. Wr Fielder informs ns that he has personal knowledge of a car whose gear-box was, experimentally, lubricated with graphite grease, a substance which must not bo confused with the colloidal product which can be mixed with fluid oils. Although this grease proved to be suitable for the gears themselves, it did not penetrate adequately to all the working parts, with the effect that play developed in a ball-race, causing noisy running. The gear-box was drained and refilled with the advised giado of oil, which was mixed with the right amount of the colloidal graphite, and it is said that since then the noise has disappeared, and that there are no audible symptoms of looseness. The product in question has not of late years been marketed widely in Australia, but is imported by fit least one Sydney house.

.When applied to the engine it may be mixed either with the oil in the sump or with the petrol, or introcVueed by means of an upper cylinder lubricator, in which case it •« blended with the upper cylinder lubricant. Jn setting out the facts recorded above no claim is. made that this special form of lubrication is a “cureall/ ' or is even devoid of certain possible disadvantages, but attention is directed to the fact that no proof of inherent bad qualities or of its unsuitability for use in lubricating oil has yet been made out, whereas there is much well-established testimony in its favour.

NO PRACTICAL SOLUTION

“DIMMING” CONDEMNED.

Despite the many inventions which have been produced to abolish glare from the headlights of the car, no practical solution of that problem has vet been adopted commercially as a general standard litting, and on a majority of the latest models no special device is provided to combat that, evil. .\iany recognised authorities have condemned “dimming’' as being essentiallv dangerous, because of the partial blinding of the driver of an approaching car, whose eyes take a perceptible time to accustom themselves to the reduced degree of illumination. In addition to that, the cutting down of the light by means of a manual control imposes too much distraction on the driver, and also engenders the risk that pedestrians and poorly-lighted vehicles might not be perceived in time to avert an accident. The regulations in New South Wales provide that the headlights of a car shall be so adjusted that any substantial object on the road ahead is easily visible from a distance of not than 2d yards, and that the lamps shall be so set that their projected beams strike a level roadway not more than 00 yards In front of Hie vehicle.

Although the position is still far from satisfactory, car owners individually can help by refraining from using headlight bulbs of unnecessarily high candle-power, and by seeing that (lie bulbs are well focussed. A majority of headlamps have parabolic reflectors, and an adjustment by means of which the position of the bulk may be altered, until it is so placed that all the beams of light projected by the reflector converge at a common point. If the bulk is so adjusted that its filament is at the right focal point, the beams arc thrown forward in parallel lines, regardless of the point on the reflector from which they are reflected.' When a bulk is so set that its filament is behind the accurate focal point, the rays diverge, and there is a diffusion of the illumination. If tho bulb is adjusted so that the filament is in front of tho focal point, then the beams of light will be reflected at acute angles, and after intersecting one another will diverge. The result in both instances is that the wrong placing of the filament with regard to the focal point of the reflector causes diffusion of the illumination

and a. black spot in the centre of the projected beams. Whereas, when the .ocusaing is correctly done the light is concentrated into a comparatively narrow width, which gives high illumination of the road ahead.

An approved method of testing for accuracy o'f bulk focus is this: From a distance of about Id feet direct the beam of each headlight in turn on to a wall, and then try the bulb adjustment, noting the dimensions- of the dark spot in the centre of the ring of light thrown on the wall. If the spot increases when the bulb is moved .rearwards, then the adjustment has been wrongly set to give a spreading beam, and the filament is behind its proper focal point. If the lamp bulb is moved, lirst of all as far as possible .backwards, and then advanced, the spot of light thrown on the Avail may grow smaller, and then Avill enlarge as the filament passes the focal point. As soon as it is observed that the spot begins to increase the adjustment should be made backwards until the smallest possible spot is obtained, as at that point the filament Avill be approximately in its right focal position.

HEADLAMP REFLECTORS. | The part which the reflector in n headlamp plays in ensuring a perfect driving light is not always appreciated by car-owners. The light which reaches the road directly from the filament represents an inconsequential part of that which should be available, most of the light being provided by the indirect rays which reach tho road from the silvered reflector. If the reflector is allowed to become dull or tarnished it absorbs light instead of reflecting it, and in consequence the intensity of tho headlamp beam is impaired. Tho reflector should therefore be kept highly polished. For Ibis purpose extremely tine silver-plate polish nr rouge should be used. More abrasive polishes, such as those used for brass, will quickly scratch and wear away the finely finished reflecting surface. Giving evidence at an inquest at Hammersmith, a car owner-driver said ho did not know how many cylinders his ear had. It is the way with some motorists. They cannot even count their sparking pings.

Rubber is the basis of a new preparation for surfacing roads, invented by a Dutch engineer. It is claimed that the resulting surface is skidproof, and that it reduces traffic noise.

MASTERY OYER CAR ESSENTIAL,

It has been asserted that good car drivers, like poets, and horsemen, are born and not made, states the “Sydney Morning Herald," but such an opinion should not deter the inexperienced motorist from striving to better his skill at the wheel and to obtain such a mastery over his ear that even in the worst emergency he will instinctively take the right action. A certain degree of. proficiency is, of course, demanded before a driving license caii be obtained; but it is a mistake for the novice to feel satisfied that because he lias been granted ix license he becomes a thoroughly competent driver. It is wisely insisted that every driver must exhibit a reasonable amount of skill before he is licensed to control a car on the public streets, but the man ,who values his own safety and comfort xvilL not rest consent with that qualification, and will continue to school himself in the art of driving.

Many motorists appear to find great difficulty in parking their cars in confined spaces, and in steering them accurately when reversing; but a little quiet practice in a secluded spot will soon (‘liable any person of ordinary aptitude to overcome such troubles. Then, too, there is the question of pro' l cision of steering, which calls for good ."judgment as well as a straight eye. From rhe driving position in the offside it is generally impossible to see the actual position of the near-side front wheel, and when it is necessary to drive as far as it is safe to "the left of the road, or to steer the car through a narrow space, an instinctive calculation must be.made as to how far the steering should be turned. Only practice will bring perfect .judgment. The enthusiast who really desires to become adept will make rapid progress if he. takes his car to some open space whore ho can try his .hand at driving in reverse, .piloting the car between two marks or sticks set up to represent a narrow gateway, and trying in how short a marked distance ho can park the vehicle close and parallel to an imaginary kerb. Much good will also result if ho makes a habit of concentrating intently when driving over different types of road, noting at what speed it is safe to take various types of eornors, and how to guide the car over rough patches, so as to avoid irregularities

and to strike gutters and ridges obliquely, thereby lessening the shock and jar to the vehicle.

RADIATIONS. Regularly clean the exterior of the sparking plugs to remove any oil or dust deposit on the insulation, which will act as a conductor and, in all probability, cause short-circuiting from this terminal to the body of the plug.

Costs of motor car operation have been much reduced as a result of the progress.whic.h has been made in. the design of bodies. The rigidity , and strength of bodies have been greatly increased by ‘ modern constructional methods, which reduce the number'of joints likely to become stressed. Modern bodies contain only about- 250 parts, compared with 700 parts in those produced a few years ago. ,

A new idea in sunshine roofs was recently devised by an English designer, a largo, non-splinterable glass window, fixed in position, taking the place of the usual sliding panel. A movable section of headlining works like a blind and covers the window fiom the inside when necessary. ,

First applied to American cars, the device for automatically starting, the engine of a ear as soon as the ignition switch is manipulated is finding, much favour with British motorists. A prominent British firm which manufactures electrical equipment for cars his designed a modified form of this device, .which will be used on many British cal's next rear.

Motor omnibus companies in London have adopted-an. interesting means of avoiding the difficulty of collecting fares in the peak periods. At the points where the majority of the traffic is collected" automatic machines, similar to the automatic stamp-selling machines, are installed to; issue tickets of various denominations. Thus,- passengers are able to ■■purchase their tickets before they board a bus, '

A Bill before the French Chamber of Deputies proposes to abolish the registration tax on motor cars and replace, it with a super-tax of “24 centimes on each litre of petrol used.” Petrol in Franco is cheaper than ever previous!}', and the now tax, while reducing the taxation on motorists, would only increase the gallon price of petrol from 1/1 to 3/3.