MOTORING & MOTORISTS

Evening Star, Issue 19919, 16 July 1928, Page 12

MOTORING & MOTORISTS

[BY RADIATOR.]

TIMES FOR LIGHTING UP. To-day 5-14 Tuesday 5-15 Wednesday ... ... ... 6.15 Thursday ... '. 5.16 Friday 5.17 Saturday 5.18 Sunday 5.19 PUBLICATION RECEIVED. ‘ Big Tree Bulletin ’ for June. HINTS AND TIPS —Making a Useful Tool. — It is possible to magnetise a file by taking about a dozen turns, of a strand of cord to which a lighted electric bulb is attached. This will give enough magnetism to the file to permit ot its use for picking up small parts—screws, nuts, etc.—that have fallen into inaccessible places. ■ —Overhead Valve Noises. — Sometimes the push rods of an overhead valve engine cause noise by what can only be called “rattling” at high speeds. ' Such trouble can, in some instances, bo cured by connecting two neighbouring push rods together with a light coil spring.

—Brake Shudder.— The works manager of a largo Loudon service depot Ims put lorward a theory which throws quite a fresh light on “shuddering” brakes. “In the old days of rear brakes only/’ he said, “ drivers were far more cautious than

Brief accounts of holiday trips, mads, and places of Interest ar® invited for this column.

they are nowadays, but now some men take almost suicidal liberties with theii car, relying on the full power of the brakes to pull them up. This loads to a tendency for brake drums to over heat, and eventually the fabric ‘ sweats ’ and deposits gummy substance on the brake drum.” He de raonstrated his point by holding up •.

drum which had just: been removed from a customer’s car. A curious fad is that the gummy deposit—emanating from a binding modium used when the fabric is compressed during manufac ture —does not disperse, bnt tends te accumulate. —Engine Mixture Economy.—

The greatest economy is not, as often supposed, obtained by cutting down the jet or adjustment to give the weakest mixture on which the car will runproperly. Economy results from the use of the mixture which gives the greatest efficiency at the speed mostly maintained. A mixture found weak for this speed requires a wider throttle or a change to al lower gear, so that the economy is more than lost. Too rich a mixture in starting, as sometimes with the use of the choke, will causi dilution of the engine oil. Start ing on a mixture too lean often causes waste in failure to start. An extra air valve -is well suited to enable the driver to obtain more easily a good running mixture when hot and a good setting for easy starting. —Reversing Fan Belt.— In some oases where a fan bolt pet sists in jumping off the pulley, it can be made to stay on by removing it and replacing it with the side that was previously in front towards the rear. The trouble is caused by a defective belt stretching more at one side than at the other. WHEEL MISALIGNMENT. A tyre abuse that has grown more rapidly probably than any other is that caused by misalignment of wheels. Under this irregularity are classified many conditions which are caused by wheels failing to run true, and in accordance with a course naturally to be expected from a car One feature of the trouble which ma owners do not appreciate is that any wheel on a car can be out of line. Rims, of course, are responsible occasionally for a wobble which may be thought to be misalignment, the wheel itself may be in perfect alignment, and yet the rim may not fit properly on the wheel, thus producing wobble. Frames of chassis may become so bent and sprung that the axtes do not run parallel, thus bringing about misalignment. The “springing” or bending may be almost imperceptible, and yet cause the trouble. Rear, as well as front, bearings may become loosened through wear-, and allow the wheels to spsead and drag. In any case of tread wear of a tyro it is ad«§.able to check all these features of the car. Misalignment disposes of the tread very quickly, as the effect is not unlike rasping the rubber off the tread. Traders specialising in tyre sales and repairs have facilities for testing alignment, and there is no charge made for the service. NEW 7 h.p. MORRIS. A WELL-KEPT SECRET. The millionaire motor magnate, Mr Morris, sprung a surprise on his competitors in Juno by"announcing that he will put a 7 h.p. car on the road. This model has been produced with the utmost secrecy, and tests have been carried out on quiet roads between midnight and 3 a.m. In the day-time the car was hidden in a lorrv, driven to secret testing roads, given a trial, and then hidden away again. A further method of cheating prying eyes was a dummy radiator used instead of the ordinary Morris radiator. Until recently only four people knew of the existence of the car, despite the system of super-spying which rivals in the motor industry employ. The new car has four cylinders, overhead valves, and four-wheel brakes. The price has not been announced. Already thousands of cars of this rating are sold throughout England, chiefly because of the low tax, the ease of garaging in crowded districts, and the cheap running costs. Indeed, so popular is it already that the existing British “ babies ” have invaded America. A FROZEN BATTERY. One hears of burst radiators caused by freezing, but a burst battery through the same cause is a rare avis. This happened to the battery of a car in Central Otago, and so powerful was the force of the explosion that the whole battery, box and all, was shattered. Only one cell really burst and caused al! the damage. On this cel) the paste in the plates was blown completely out, and the bridges and posts considerably twisted. The Exide Battery Company, into whose hands the battery came for repair, explains that a battery will only freeze when it is in an uncharged or only partially charged condition, so it behoves motorists to see that their batteries are kept fully charged during the winter months, or a similar accident as befel the Otago Central motorist might happen. CLUTCH SLIPPING. A SIMPLE TEST. The easiest way to test for clutch slippage is to simply try letting in the clutch white the gears are in low and the engine is running. Of course, the car must bo standing still and the brake tightly set. Under normal conditions the engine should stall '.ho instant the pedal is back far enough to engage the clutch. If the engine continues to run without pulling the ear, or even shows a disposition to make some headway against the blockade, it is a sure sign that the clutch plates are not holding. In making this test, be caretul to consider the possibility of the engine continuing to run through pulling the whole ear. Some of the new engines will pull the car even with the holding brake sot. differential operation. The new motorist, who may be puzzled regarding the operation of the differential, will find that it is not such a complicated piece of mechanism as the name might suggest._ In the first place, it is not an essential, but a desirable part of a car s mechanical make-up. The power of the engine, of course, is transmitted to the two rear wheels, and when a cal goes around a corner it is necessary that the outer wheel travels much .faster than the inner one. To accomplish this without causing undue _ mechanical strains and tyre wear, a differential is fitted in the rear axle. The most common form consists of four bevel pinions mounted on. the differential spider, and contained in a case. In the case is mounted the driving gear, which is driven by the driving pinion on the end of the propeller shaft. Bevel pinions on the ends of the axle shafts mesh with the four “compensating, or differential, gears. As long as the car travels straight ahead, and the resistance’ of both rear wheels is the same, these gears do not turn, \vhon

;oing around a curve greater resistance ■s offered to the inside wheel, and the •ompensating gears permit the outside vheel to revolve faster than the inside .vheel. Actually the inside wheel could w stationary, or even revolve backwards. The differentia) also divides he driving force delivered to the two rear wheels equally between them. II he road resistance is not equal at* the two wheels one will slip on the road,, uid it the difference is very great one will revolve rapidly while the other remains stationary, and the car will not move. For instance, if one wheel is jacked up, the engine started, and a near engaged, the wheel will revolve, uo power at all being transmitted to the wheel which remains on the ground.

EMERGENCY BRAKE NEGLECTED.

CULTIVATE INSTINCTIVE USE. Wider use of the emergency brake might help people to live longer, said a member of New York’s traffic department recently. In almost every examination of a truck or taxicab or other car, driven by a professional driver which had figured in an accident, the emergency brake was found set, he added. Such cars, driven by their mvners, on the other hand, are almost invariably found with the emergency brake not in use. Faced by a sudden emergency, the non-professional jams his foot down hard on the foot brake, entirely neglecting the emergency. Obviously two sets of brakes will stop a car in less time than one set. And the foot brake, in use all the time, may be loose, may have a worn lining, may be ineffective for many reasons. While the emergency brake, seldom used m pleasure cars, is for that reason almost always in excellent condition. The man who drives his own car should take pains to school himself to use the hand brake when in a light place. He should practice doing this, so that, when faced by the necessity for stopping his car within a few yards, nis hand will as instinctively turn to the emergency brake lever as his feet to the clutch and foot brake. Don’t forget the emergency brake! Learn to use it by instinct.

WATER-PROOFING DICKY SEATS.

Occasional showers in summer time frequently mean a drenching for the unfortunate passengers in the dicky seat of a car, for in most cases they will not be provided with the waterproofs and other protections against inclement weather which are usually carried in winter time.

One source of trouble which is particularly annoying to the dicky-seat passengers is the leakage of raindrops down the rear of the hood, over the slope of the tail of the car and down into the dicky seat, dripping on to the passengers' feet. To cure this trouble a shallow gutter should be fixed to the forward edge, and arranged at a slight angle to give a fall to the water which drips from the hood. The gutter mav be of sheet metal enamelled to match the bodywork, and screwed to the top of tly rear part of the car in front of the dicky scat.

FIRE RISKS

SOME FLARE-UP CAUSES

A frequent cause of firo is the leakage of the carburettor or the pipes leading to it. Sometimes a union in the petrol supply pipe between the tank tap and the carburettor is troublesome. It may not leak badly, but when the car is parked or garaged there will accumulate a layer of petrol in the float. Some of these leaks are hard to find. It takes considerable time to locate them, since the petrol vaporises almost as rapidly as it leaks out and the surface may seem dry. But the inflammable gas is being made, and is dangerous. A badly seating float chamber needle valve is a very frequent cause of petrol leaks which may be dangerous. When the engine is running this is not so serious, as the petrol may be drawn fast enough to prevent flooding. But when the engine' is at rest the float chamber will overflow, and the results may be dangerous. This petrol-impregnated air may be ignited by a spark. Even the spark which may occur at the contact breaker of the magneto or of the coil and accumulator system may cause a flare up if the air is carrying petrol fumes. This may occur after the car has been at rest with the engine stopped, and on the first attempt to start the motor. Cases have been known where the sparking of the brushes of the commutator of a starting motor have caused a flare-up when petrol gas has been under the bonnet or lying, as petrol gas will lie, in the apron under the engine. It is almost impossible to guard against the chance of such a happening, except by ensuring that petrol is not leaking anywhere. In the case of the garage the same conditions arise. The car loft standing should have the petrol turned off. It is a good plan in tho case of pressure feed petrol tanks—where tho petrol is under pressure from a pump as in many cases —to release the pressure when leaving the car for any time in the garage. These pressure tanks are almost invariably below the level of the carburettor, hence the need for a pressure above the fuel to lift it to the carburettor. If the pressure is released (by unscrewing the filling cap) there will be no chance of petrol leakage in the pipes, since the fuel is led from the bottom of tho tank by a pipe which leads out at the top and the easing of the pressure prevents absolutely any petrol leaving the tank. It will, of course, be necessary to close the filling orifice, then the petrol is practically hermetically sealed and safely contains! m the tank.

WHY DOES RUBBER PERISH? Tho ageing, or perishing, of rubber is a problem which has confronted the rubber industry from its commencement. It is generally agreed that the ageing of rubber is due to the oxidisation which rubber is known to undergo on keeping, and tho question before chemists is to find means to prevent this oxidisation. Light and heat are known to disfavour oxidisation, and it is thought that protection against the action of light might be produced by the addition of suitable organic dyes dissolved in the rubber. Many compounding ingredients might actually improve the resistance towards ageing, while attention has been given to the use of anti-oxidants; that is, substances which would inhibit the union of the rubber molecule with oxygen. In this respect the_ use of organic substances containing several amino or hydroxylic groups has been the subject of a recent patent. The degree to which vulcanisation is carried is also an important point with regard to keeping qualities, over-curing to bo rigidly avoided. It is essential that a rubber manufacturer should have some idea of the

CORRECT INFLATION GIVES GREATER MILEAGE.

probable life of his products, so various laboratory tests have been devised to turnish this information. The oldest for: ot ageing test was performed by heating the samples in an air oven and noting the increase in oxygen. In the weather test samples are exposed to bright sunlight for prolonged periods, but as sunshine is a variable quantity in this country they are now enclosed in a' cabinet and subjected to ultraviolet rays produced by a mercury vapour lamp. During the war samples of balloon fibre were even transported to Africa to be exnosed to the tropical ™fhose tests are, however, rough, and great care has to be taken in the interpretation of the results if erroneous conclusions are to be avoided. One thing admitted by everyone, but so far unexplainable, is that any rubber article in constant use outlasted similar articles made at the same time but kept in storage.

CNDERINFLATION STOPPED BY CHECKING OF VALVES.

Valves, particularly m balloon tubes, often condemned as leaky, frequently just need the caps applied or the caps tightened. In a recent check of cars parked in a street the development department of the Goodyear Tyre and Rubber Company examined a total of 189 tvres, including spares, on over forty ” cars. Of this number, 71 tyres, o. 41 per cent, either had no valve cap or the caps had not been screwed down tight enough to seal the end of the valve. Of the •?!, eighteen were leaking through the valve, and could have beon corrected bv a very simple operation The valve plunger which is responsible for holding the pressure within the tyre is a delicate-piece of mechanismperfect functioning of this plunger is dependent upon obtaining a perfect seating of the brass cone into the little rubber gasket in the cup which is placed at the top of the spring. Each time a tyre is inflated, the plunger seating or seal must be broken to permit the entrance of air. In many cases, while inflating a tyre, a very small particle of dirt, mixed with grease or wet air, may become lodged upon the little rubber gasket, and prevent, tha re-establishing of the perfect seating that had previously existed between the brass cone and the rubber gasket. This leak may be slow, and not noticeable to the car owner, unless he takes the trouble to test, each valve after such inflation. It is a condition, however, that does exist, and to some extent is the factor that is contributing to the necessity for more frequent reinllation of balloon tyres. And, unfortunately, it is a condition that cannot bo definitely controlled. However, in terms of loss of pressure in pounds per week, the pressure loss in the balloon bubo to-day is no greater than it is in the high-pressure tube. In the case of high-pressure tyres, the user inflates to 601 b or 701 h pressure, and he has a tube of comparatively smaller volume capacity. For balloons, usually 301 bto 351 b pressure is the inflating figure, and tin tube is of very much greater volume capacity. The average car owner judges the need of reinflation bv the appearance of the tyres rather than by chocking the gauge. The high-pressure tyre,_ being small in cross section and having been inflated to a much higher pressure in the beginning, naturally runs longer, before taking on the appearance of needing more air, than the balloon tyre ij'hich started out at 301 b pressure. At 251 b, a drop of 51b, it begins to look badly deflated. Based on the laboratory and road tests, the opinion is that the normal loss of pressure by diffusion with reference to time can be expressed as a percentage. For example, it can be said that the average tube leaks 10 per cent per week. This means that as the pressure decreases due to leakage, the amount also decreases, but the amount is still 10 per cent, of the pressure. Actual observation on the road inticates that the pressure loss ranges from 211. to 3jlh per week. Present indications aro that during warm weather the loss comes nearer the higher figures, and with lower temperatures the loss will he nearer the lower Those figures also vary somewhat with tyre sizes. However, if no valve cap or dust can is used, there is no secondary airtight seal, and tho (fir pressure goes down much faster. And with balloon tyres, the necessity for keeping up the pressure is of far greater importance than formerly.

OIL BORING IN THE DOMINION. Petroleum oil is elusive. It would seem that tho oil which does not bubble up to the surface on its own accord was engaged in a game of hide and seek with man. But tho great future and riches which lie before those who can discover oil in commercial quantities has caused much speculation, many disappointments, and not a little gambling in the dominion (states the ‘ Big Ireo Bulletin’). , ! Those who have money to invest do not hesitate to do so when there is the least possibility of oil being encountered. Even if oil has not been met with in profitable bulk, hopes have been raised by small quantities that seem to indicate greater possibilities. The Government of New Zealand has always looked upon the discovery of petroleum in sufficient _ quantities to have a commercial working _ value as a likely happening in the dominion. They have staked their money on it in bonuses, subsidies, and loans to tho searcher after oil. As might be expected, the support ox tho Government has, caused considerable activity. In twenty-six cases have boro holes been drilled during recent years. Drilling still continues in parte of Taranaki, Hawke’s Bay, Canterbiuy, and Westland Some of the borings have reached great depths in the search for this eluoil. Tho deepest is that at Moturoa, near Now Plymouth, which lias attained a depth of over 6,000 ft. Oil has been found in this working, but, although tho quality was good, the flow was too slow and intermittent to be of great value Taranaki has been the scene of much concentration for oil seekers. At the beginning of 1925 drilling operations j were commenced atTarata, and also on the foreshore at Moturoa. By tho end of the year the well at Tarata had reached a depth of 4,130 ft, but no oil had been found. Tho bore hole on the foreshore at Moturoa was more ful and a good show of oil was found at’93oft. Not satisfied, however, tho drillers went further, and at 1,550 ft, or thereabouts, a high-pressure gas was encountered which buoyed up the hopes of the drillers more and more. Any holies that were experienced relating to , gas were futile, for the gas was found to be unfit for fuel. On analysis it was said to contain 72 per cent, carbon dioxide and only 25 per cent, of methane and its homologues. Again, at 2,200 ft, the Moturoa well proved a disappointment to the borers, for at this depth, judging by other experiments in the vicinity, an oil sand should have been touched. This was not done. Before the well reached 2,600 ft a good show of oil was found, but not sufficient in quantity to be profitably exploited. So boring went on. 11m depth is now well over 3,000 ft. In many other parts of Taranaki on experts have carried out field work in the hope of finding areas ol land with a structure suitable for the retention of oil This work still proceeds. The district in and around Gisborne is also thought to be oil bearing, and several favourable structure of land have been located, and drilling is in progress. Again, near the Mangles River, in the Murchison district, on seepages occur which are now being drilled Elusive as oil seems in this countiy, it may yet be traced in workable quantities, and searchers for it aro offered every facility.

ma CYGLSHG i FIXTURE. The monthly meeting of the motor cycle section of the O.M.C. will be held on Wednesday, July 18. NEW ZEALANDER AT EDINBURGH. The new sport of dirt track motor cycle racing was introduced to Edinburgh on May 19, when a crowd of between 5,000 and 6,0Q0 witnessed the events run by the Scottish Dirt Track Racing Club at the pew enclosure _ in Seafield road, adjoining the Marine Gardens. The events comprised a Scottish one mile invitation race, an international contest for the Scottish gold ■ helmet,_ and an open invitation race. The prize money totalled about £IOO. The riders included Paddy Dean (Australia), the world’s champion; “Sprouts” Elder (U.S.A.), who broke record at Glasgow recently; and Stew--1 art St. George (New Zealand), Ivor Creek, the English champion, and George Meredith, Australia, were also competitors, in addition to a number I of Scottish riders. It was interesting to note that bookmakers were admitted to the track, the .first occasion on which, the sporting j gentry have been allowed at a dir! ] track meeting in Scotland, the A.C.U. having banned all wagering | i The proceedings started with a par j ado a. the riders, and the Home Coun- ' try and Australian racers were enthusiastically cheered. St. George was in the final for the golden helmet and £25 prize money

against M‘Queen, the Edinburgh rider. The lattoi looked like making a light for the honour, but in tfic end the New Zealander, as in Glasgow, when ho won the golden gauntlet, '-ion oy 4yds. It subsequently transpired that Im had ridden three, laps ol the six in tho race with his rear lyre oil th: rimBOWDEN HINTS. With Bowden mechanism it not infrequently hapi*cns that all the available adjustment is taken up, with the result that the inner cable must be shortened and the nipple resoldercd in its new position The same effect, however, may bo obtained_ by lengthening tiie outer casing, if soldering facilities are not available at the moment. This can be easily dono_ by screwing the adjusting sleeve right home and pulling back the outer casing as far as possible, leaving the inner cable exposed. A piece of copper tuba of, roughly, the same internal bore and externa] diameter as the outer casing is then cut to the_ length oi the exposed portion of the inner cable and split by a hacksaw cut lensrtmnse. This is then opened out to slip over tho cable, and is closed up again wit!; a pair of pliers when in position. The con ct adjustment of the cable may rime he ma f te u.th adjusting sh--' -- r ml lock mil iii the usual way A! though this is purely a temporal';, measure, it will he icnnd to be both effective and reliable for an indefinite period, and has the advantage of giving a reserve of adjustment by virtue of having set the adjusting sleeve at tho “zero” position by the insertion of the split distance piece.

If Bowden cables are not lubricatco regularly they become still and are apt to break. There are many methods of lubricating them, but J have found the following method to be the quickest and most effective;—First detach the cable from the control and slip oyer it a short length of rubber tubing (acetylene gas tubing serves admirably); next disconnect the pipe from the hand oil pump and connect the other end of the rubber tubing to it. When the plunger is depressed oil will lie forced through the entire length of the cable.— ‘ Motor Cycling.’ MOTOR HUMOUR Fair One: “Now, before we start for this ride I want to tell you that I don’t smoke, drink, or pet; I visit no roadside houses, and ] expect to be home by 10 o’clock.” Young Gallant: “You’re mistaken.’’ “ Yon mean that I do any oi those things?”“No. I mean about star)in" mthis ritle.”—Bifc.’ • “ ft’-- )• ' man ' n an c\: >■? ■ ; knon 'll o-t (T-i-rv , ' i..,,'.,,/ ’,ll’ ~1 1 .. : j'mrm': '/ \ C' rl.-itf, C.:: who hud iniverti'--' A that he urn pn. a car together in -seven ana -te> wap rung up on the phone and asked ii it was true. “Yes,” was the answer; “why? “ Oh, nothing. But I believe I’ve got tho car.”