MOTORING & MOTORISTS

Evening Star, Issue 19842, 16 April 1928, Page 10

MOTORING & MOTORISTS

TIME FOR LIGHTING UP.

, FIXTURES

April 17.—(LM.C. monthly meeting. April IS.—Motor cycle monthly meeting. April 2S.—Motor cycle paper .chase. May 12.—Motor cycle sporting trial. TYRE PHENOMENON. PUNCTURES AND CENTRIFUGAL FORCE. The successful attack hy Captain Malcolm Campbell upon Segrave’s 203 m.p.h. record once again focuses the attention of the motonng community upon the subject of ultra-high road speeds and the phenomenon to which they give rise (states the ‘Motor’)- In this connection it has on several occasions been pointed out that for recordbreaking cars of this kind special tyres have to bo constructed, the treads of which are made as thin as possible (consistent with safety)' in order to minimise the disruptive effects of centrifugal force. This force is, of course, occasioned by the tendency of any moving weight to continue its motion in a straight line, so that it resists being compelled to follow a circular path. Consequently, every ounce of rubber in the tread of if 30in tyre rotating at about 2,000 r.p.m. is pulling outwards radially away from the hub with a force of about 1001 b.

[BY RADIATOR.]

futuristic.

PROFESSOR’S FORECAST

This action of centrifugal force in the tyres may give rise to a very peculiar phenomenon should the air pressure within the tube be suddenly released by a puncture or burst. Wo believe that the late Mr Parry Thomas was the first to notice this effect, as he told the Dunlop Company some years ago that when he experienced a burst at a speed of 120 m.p.h. or so the car, instead of dropping on the side on which the burst occurred, would actually give the impression of rising slightly. Furthermore, the unmistakable shaking and discomfort caused by the rim running on the track with a flat tyre was not experienced .until tiie speed of the ear was reduced quite considerably.

An investigation on the testing machines used in the experimental department at Ford Dunlop led to the conclusion that the sudden release of air pressure within the tyre allowed centrifugal force, acting upon the tread, to pull the cover out into an extended egg section, so actually increasing the distance between the rim and the track so soon as a hurst occurred. This gives rise to all sorts of intriguing speculations, such ns the question of whether it _ would lie possible to run with no air at all in any of the tyres, provided that a sufficiently high speed could be maintained! UNDINE VIBRATION. Engine vibration has always been one of the worst enemies of the automobile designer, and if the foe has been driven further into the background, even to-day he has not been entirely beaten, says the ‘ Autocar.’ \ ij)ration is like an assassin, it skulks in the background and creeps out at awkward moments. Also its effects arc difficult to measure, and a community of little vibrations can get into step together, and, by pushing at the right moment, can make an otherwise innocent mass of metal behave like a rogue elephant. TUBE CONSERVATION. A tyre expert of the Goodyear Tyre and Rubber Company, Ltd., gives the following hints on tube conservation: — Be sure to use the proper size of tube in the cover, it changing a coyer from regular size to oversize or ice versa, the tube should also he changed. Always use a Hap with a straight side cover, except when it is used on a drop centre or well base rim. Ne\cr use a flap with a beaded edge tyro. Before fitting a new tube examine the lock nut at the base of the valve, and tighten it if necessary. Rims should bo kept free from rust and painted when necessary. Bent rims should be straightened. , The inside of the cover should be kept clear from dirt and grit of any k'Valve caps and dust caps should always be kept well tightened.

DO NOT LIKE IT,

TAR AND THE MOTORIST

Tar is anathema to .motorists.

They do not like it. Some of them like the smell ol it, but they object to having to cat it. And as for putting it on roads— tvcll, just a little—very little. Tim other day tar that had been laid years ago came to lile, says the Sydney ‘Daily Telegraph.' Jt melted under the glare ol the record heat, it ran in little rivulets on the side ol the roads; it squelched under the tyre treads. Motorists cursed sottly d they had passengers in their cars—some outright if they were by themselves. Tar-splashed cars wore a common sight in the suburbs. As the motorist passed over a particularly inviting patch of tar he went gingerly. Memories of previous encounters held him in cheek. Tar does not come off a. car easily. It has to be attacked desperately, much “elbow grease” must be used, and even’then the tar has the last laugh. Perhaps the reason why so many dark-hued cars are seen in New South Wales is due in some measure to the clinging propensities of the tar. Gaily colored cars fare badly on our roads. But ivhere tar—road tar—becomes ■the biggest nuisance is when it splashes the faces, hands, and clothes. Many joy-riders in back scats have sad memories of past events. Lithgow Council has refused its tar men an extra shilling a day. Many motorists would pay the extra shilling to them if they refrained from using tar —at least, not quite so much of it. A TRIAD RUN. Some private owners when trying to sell a car do not handle the trial run in quite the manner that an expert would adopt. They are prone to talk too much. This is not meant to infer that sellers should gloss over obvious faults, but it is unnecessary to allude to the fact when an engine knocks slightly on a bill, or when it is necessary to change gear on a gradient that the car ought to climb in top. The prospective purchaser of a second-hand car goes out for a trial run because ho wishes to observe for himself how the vehicle runs. That being so, the wisest course to adopt is to drive in the ' ordinary way, not trying any stunts on steep hills, or speed bursts on the level, unless such demonstration is specially requested. It is far better to let the prospective buyer do the talking, if a man has been persuaded to take a trial run, he is prob-

AUTOMOBILE HOTEL

SERVICE

Brief accounts of hoDday trips, roads, and places of interest are invited for this column.

ably keen on the car already, and likely to purchase if he approves of its running. Hence it is better not to talk too much, even in praise of the car; but to let its obvious merits sink in. and to concentrate on the driving. Given a car in moderately good condition, there is no need to do more than drive it around in a reasonable way, and to show off its paces without ostentation. One last word—if there is anything that is radically wrong with the car, such as a broken spring leaf, or a leaking radiator, it is far better to point the fact out at the onset, rather than to have it found out by the would-be purchaser after the deal lias been concluded. PORTABLE STARTERS. Portable air-cooled engines are used in a number of large commercial vehicle garages in Great Britain to effect starts when the fleets are being taken out for the day. Many buses and trucks do not carry self-starters, and even where these are fitted the work of turning over a largo engine in an English winter is a heavy tax on the battery. By the laborious hand-start-ing, method very rich and wasteful petrol mixtures have to ho used, and a prompt start may be impossible. The portable starting plants consist of a. twin cylinder motor cycle engine geared to a‘universally jointed spindle which grips the starting handle. The starter" may be wheeled around the garage, and a. score of engines can be started in a few minutes.

That it will ho possible to drive 300 miles an hour in a completely onginoIcss car about eighty years liouwms the opinion of Professor Low, English scientist.

Me thinks cars will then ho governed by tho principles of perpetual motion, in which science is making considerable strides. Cars of tho future, according to the professor, will bo fitted with radio telephone and television, and will he so easy to operate that, a driver will be able to sco and speak- to bis friends at homo while travelling, holding wings will eventually bo fitted to cars, enabling motorists to make long-dislnnc-c air and ocean trips. Ho did not add—though it seems a first necessity—that pedestrians will then no longer exist. FARR fC ROD! ES. Of fairy lightness, but at the same time strong and durable, modern fabric coaehwork is having a very pronounced effect on motoring in England, it is this new typo of body construction that is largelv responsible for tho closed-car boom. Jn fact, it is not too much to state that in the case of very small and low-powered cars without the use of fabric closed motoring would scarcely he possible. The extent to which the development of tins now achievement in coaehwork has cheapened motoring in Groat Rritain is not generally appreciated. One of the first assets of this type of body is lightness, ami in motoring this is a Highly important factor. Take the case of one wellknown small fabric body mounted on a 7 h.n. saloon. This body actually weighs 14Ib less than the standard open model of this particular car. Reduced weight means improved road performance. Tyre wear is reduced, petrol comminution is lower, and the weal and tear on the engine loss. In some cases the closed fabric saloon is actually faster than the coachbuilt open car. There arc quite a number of mi.s(conceutions about . fabric coaehwork. Some people imagine that the fabric merelv takes tho place of paint and varnish. This is far from the case. Fabric is used in connection ivit.li entirely new methods ol motor body construction representing a very definite advance. Methods vary, hut in nearly every case results arc satisfactory. In one case the fabric is stretched over a rigid and solid structure of three-ply wood flexiblv attached to the chassis Here tho body is entirely _ insulated from road shocks and vibration. The result is complete silence and absence from body drumming under all conditions. There arc different methods of building up fabric bodies and different methods of suspension, hut liccdom from vibration and silence arc features common to all the best types. On rough roads tho smooth ruling (pi.vltties of this typo of coaehwork are a revelation. It is lor this reason that Continental car makers have almost generally adopted fabric. At tho last Paris motor show coachbuilt bodies of tho normal typo looked quite oldfashioned. r .l ho cpiGstion natniully arises as to whether fabric is durable. It has now been in use long enough to answer this question in the affirmative. There is also this advantage: Should tho fabric become damaged in any way it can very easily be repaired. The actual framework for tho fabric is certainly as durable as ordinary coachwork. It is no more difficult to look after than the modern cellulose finishes. Li some cases fabric bodies are finished in cellulose. In either ease tho bodv, when cleaning is required, should be, washed down, sponged, and finished with a leather just in Hie same way as with ordinary enamelled coachwork.

CARS HANDLED RV ELECTRICAL

A twenty-eight story“ in of or hotel,” with accommodation for 1.050 automobiles, will bo erected in East Fortythird street. Now York, on a site purerased by the Kent Antonia tie Parking Garage (Inc.), according to an announcement just made by them. The garage will be equipped to deliver six motor cars simultaneously, with a possible speed of twelve deliveries a. minute, Mr Milton A, Kent, a director of the company, said. The specifications for the building include a modern automobile laundry, space where owners or chauffeurs can make their own minor repairs, a largo chauffeurs’ room, and waiting rooms. “In this proposed building,” Mr Kent said, “there will bo no cars stored on the ground floor, as the whole floor is devoted entirely to the handling of incoming and outgoing ears. The customer drives into the garage, shuts off Ids motor, accepts his cheek and leaves. From that time until he himself starts his motor to drive the car away his automobile is never moved by its own power. All handling and parking of the automobile while in the building are don© entirely by electric service.” MORE H.F. Despite the manner in which they have developed high efficiency engines, British car manufacturers in their 1928 programme are driving deeply into the Idgher horse-power fields previously exploited almost solely by makers in other, countries. Naturally, the lower rated, economical productions are still the more numerous. But as many of these have 10 to 12 h.p. motors which develop from 25 to 45 h.p., they arc designed to combine high speed and reliability with low running costs.

There are actually 12-1 different power ratings in cars now turned out in Great Britain, and the range extends from 7 h.p. to 50 h.p., from the easily-parked “baby” to the sumptuous 12-cylinder limousines that look to be worth every pound they cost. Analysis of these power ratings shows how British domestic consumption is being supplied, while the demands of overseas users have also received attention. —Distribution of Power.— Four are rated at 7 h.p., one at 8 h.p., 10 at 10 h.p., 8 at 11 h.p., 19 at 13 h.p., 16 at 14 h.p., 7 at 15 h.p., 13 h.p , 16 at 14 h.p., 7 at 15 h.p. Id at 16 h.p., 2 at 17 h.p., 4 at 18 h.p., 21 at 20 h.p., 4 at 25 h.p., 5 at 30 h.p., 2 at 35 h.p., 3 at 40 h.p., and 1 at 50 h.p. These arc 11.A.C. ratings, the minimum power flow from the engines, and the developments in many instances are extraordinary. Such an enormous power range should assist Great Britain’s efforts to dominate its overseas markets. It will he seen that 12 h.p., U h.p., and 20 h.p models are leading the production field. These are the sizes most in demand amongst buyers who want cars to fulfil all purposes. SPARK PLUG SPACES. A service engineer with twenty-six years’ experience, and in constant contact with many makes of car, says that one becomes daily more surprised at the constant magneto troubles and defective running of engines, as well as bad starting, which is due to the gap adjustment of sparking plugs. The correct setting is 10-l,oooin (ten one-thousandth of an inch) thickness, and should not, in any instance, exceed 12-l,oooin. Where coil ignition is used a 25-l,oooin maximum should bo given. Any increase on these distances puts an over-load on the secondary windings, and results in breakdowns of insulation. Another fallacy is that, when an owner purchases a set ol plugs he assumes that the gaps are correct. In all cases, new or otherwise, plugs should be correctly and carefully set. SEEING THINGS. in their recent motor car tour around Australia Messrs Mayor and Woodward, who drove 9,656 miles in thirty-seven days, had to spend long intervals, alternately, at the wheel, aid naturally suffered at times from fatigue. “ One of the worst troubles,’' saitfMr Mayor, alter the tour, “was road blindness, a curious mental state brought about by continuous driving at high speed, which mamtests itself in a queer fashion. One sees things that are not on the road, and sometimes, unfortunately, one doesn’t see things that are on the road. The effect is purely psychological. For example, on one occasion J thought 1 saw on the road in front a gate-" outlined with perfect distinctness. I jammed on the. brakes and got out of the car, but the gate was no longer to bo seen—it had disappeared like a mirage. Similar experiences with imaginary horses and people happened both during the day and nightdriving. ' This was probably because we drove alternately until exhausted.” THE SPEEDOMETER CABLE. The speedometer cable should ho inspected occasionally, and tied to convenient parts of the frame if there is a tendency for sharp bends to develop. Easy curves will lessen the wear on tho drive, while a sharp bend will usually snap the link type of core. The cable "should be lubricated by pouring in warm oil of heavy grade. _ Light grease may also be used, and it will be necessary to heat it to fill the flexible casing. A rubber tube slipped over the top of the cable will assist in the introduction of the lubricant.

CARS INCREASE

RUT LEAVER MAKERS

ft is interesting and signiiiccnt to note the reduction in the. numebr of manufacturers that has gone on steadily in the last few years, as revealed at the American motor shows. A table compiled by Automobile Industries shows that eighty-seven manufacturers exhibited in the New York show in 1922, ami only forty-three in 1928, which means not that relatively fewer manufacturers are exhibiting, but that there arc fewer in the industry, as, with one exception, all the large-scale producers have been consistently represented in the New York show. Nor does tho comparison mean that fewer cars are being produced The 1922 show followed a year in which 1,452,902 passenger cars' were manufactured in the United States, whereas in 1927, the v»ar preceding the, 1928 show, 3.066,000 ears were made. Thus forty-four manufacturers made more than twice as manv cars that rear ns eighty-seven did in 1921.

This tendency towards tho concentration of motor car manufacture in fewer and fewer producers has been marked since 1921. There were 87 exhibitors in Hie show immediately following that year, 78 the next year, 73 the next. 61 the next, 52 the next, 44 the next, and 43 in 1928. How much longer this will go on is one of tho present speculations of the industry.

WHEEL SPIN

TIP TO DEFLATE. The Dunedin motorist is unlikely to encounter a snowdrift in the ordinary course of his travels, but in America and England snrli is frequently the case. ‘ Motor News ’ offers a suggestion which provides interesting reading, more, particularly as tho principle involved is a good one to adopt when there is a rough patch of road or loose metal to cross, or one of those narrow stony fords, so common ton our country roads to negotiate. ‘ Motor News ’ warns drivers against attempting to plough through a snowdrift with the clutch in and tho throttle open. This will only spin the rear wheels and hum out the clutch. The method of attack, it is explained, is to charge the drift from a distance of 10ft or 15ft, throwing out the clutch as the drift is struck. “If the momentum doesn’t carry you over, hack up and charge again. A few such attacks will put yon over the drfit. unless it is too high) thick, and soft to be stormed at all. In that case, the only thing to do is to get out and shovel. _ “Sometimes it is mud instead of snow that makes the rear wheels attempt a reyolution-per-mimite record without getting anywhere. When this

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