MOTORING & MOTORISTS

Evening Star, Issue 21317, 23 January 1933, Page 13

MOTORING & MOTORISTS

[BY RADIATOR.]

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

LIGHTING-UP TIMES. To-day ... ... ... ... 5.51 Tuesday 8.51 Wednesday 8.50 Tluirsday 8.49 Friday 8.48 Saturday ~ 8.47 Sunday 8.46 PUBLICATION RECEIVED. Tlio ‘ Radiator ’ for January. CAUSES OF PISTON SLAP. Piston slap is a term associated by most motorists with a noise in the engine when ib is started up from cold, only to disappear when the engine has wanned up, but few owner-drivers have a clear conception of the reason of its temporary and disconcerting noise. Piston slap is caused often by the slack fitting of aluminium pistons in the cylinders, and the noise occurs through the reversal- of the side thrust on the pistons. This reversal of thrust is at its maximum between the compression and firing strokes. When a piston is moving upwards the connecting rod is not vertical, but at an angle to the cylinder, walls, and this naturally forces the piston sideways. As the piston reaches top dead-centre, the connecting rod becomes vertical, but on the down stroke it again assumes an angle, but this time the angle is on tho oppsite side of the vertical, with the result that the piston is forced against the opposite side of the cylinder. These side thrusts or “ slaps ” against the cylinder walls are intensified by the compression and explosion pressures. Piston slap is not necessarily due to wear, but may be attributable to the fact that a liberal working clearance has been allowed for a light alloy piston to expand as it heats Tip. Nowadays, through the use of special alloys and the combination of scientific design with tho introduction of special invar-steel struts, most modern aluminium alloy pistons are made with an extremely low coefficient of expansion. That characteristic enables this typo of piston to bo installed with even less clearance than cast-iron pistons, and eliminates the need for the. loose fitting that causes piston slap. VALUABLE DATA COLLECTED. .Data which may form the basis of the motor-driving tests of the future has been obtained by tho National Institute of Industrial Psychology as a result of eighteen months’ research into the responses to psychological tests of a largo number of drivers, says tho ‘ Observer ’ (London). The Minister of Transport, who referred to tests of this kind in a recent speech, has expressed his interest in the institute’s work, and, it is understood, intends to investigate the experiment. . The mounting accident roll is causing ah increasing' body of expert opinion l to take the view that some sort of psychological test is necessary to weed out tho “ accident-prone ” or-tempera-mentally unfitted driver, for with cars becoming more and more simple to drive it is felt'that the value of ordinary practical tests is becoming correspondingly less, as it is impossible to ascertain how the driver would act in a moment of real emergency, where a decision had to be taken in a fraction of a second. Some remarkably interesting facts concerning the mental and nervous qualities of good and bad drivers are being learnt from the institute’s eperiments, which consist largely of testing lorry and bus drivers and comparing the results with the driving records of the men. In tho majority of cases it is found that the results of tho tests are completely borne out by the driver’s record. All sorts of ingenious contrivances have been evolved to gauge the driver’s capabilities and measure his nervous reaction. I submitted to the whole series of tests yesterday, writes a representative of the ‘ Observer,’ and it was an unusually interesting experiment in view of a driving experience of some hundred thousand miles. For the first test I sat in a dark room with my hand on three press buttons, coloured red, yellow, and green, in varying order, and it was my task to press an appropriate button as soon as a spot appeared on tho screen. The time it took mo to do this was recorded automatically. - A SEVERE TEST. It is an excellent test of how quickly one can respond to unexpected circumstances, for the room, being dark, one cannot see which button to press, it being necessary to memorise their position while tho coloured spot appears on the screen for only a second. Not cpntent with that, however, they next repeat the test, but this time an exciting film is shown on the screen, the object being to find out whether you are easily distracted. In most eases the time which elapses before the button is pressed shows an increase compared with the first test. The next test is, I think, of considerable practical value to motorists, for it enables the capacity for judging distances to bo accurately measured. Two models are set moving . along a platform, one model being started some distance behind tho other, but travelling at a faster speed. Presently both models disappear behind a wall, and I was asked to estimate at exactly which point the one would overtake the other. There aro numbers on the wall so that any point may be indicated. This test is repeated with the models moving at various speeds, and finally they are started at opposite ends and both disappear behind the wall in the middle, it being necessary to estimate at which point they will pass each other. EYESIGHT. There are eyesight tests, measuring the times one’s eyes take to recover normal vision, after being subjected to a dazzling light; and measuring tho “ balance ” of the eye and tho flexibility of tho muscles. And then there is a delightful apparatus which enables you to motor all over tho countrv while remaining in the laboratory o! tho institute. Or so it seems. You sit in what appears to bo a car, complete with steering wheel, and you press tho accelerator and at once an illusion of movement is created and the car appears to move along a pleasant country road which is shown on the screen in front of you. Actually it is the screen vision which moves, but you can steer all over tho road and round corners; you can accelerate and put on tho brakes. And your progress is being mapped out on a graph, wiiicii will show’ exactly how fast you took tho corners, and whether you keep to tho left. The apparatus is unique and mechanism something of a secret. At tho end of the test, when tho various figures and were

worked out, it was discovered that my driving is equal to that of an average lorry driver. That is, of course, the only !,va;lablo standard at the moment. VALUABLE DATA. ' Wo do not claim that onr tests arc infallible,” Dr G. H. Miles, director of the Institute, told me. “ But the tests wa have made with the drivers whoso records wc can see aro providing valuable data. Wo have not yet established a definite 1 normal ’ by which all drivers could be judged, but wo arc preparing a basis lor that by classifying our results. For instance, hero is one batch of bus drivers tested, their accidents per year ranging Irom to C.G. Those figures indicate the accuracy of the tests

“ In Paris bus drivers have been put through somewhat similar tests for a period of seven years, and it has been found that their accidents have not increased at anything like the same proportion as other street accidents. This is, of course, due to tho discovery of the bad drivers. They can in many cases be taught and their faults corrected. An interesting thing we have found is that tho driver with the quickest nervous response lias not always the best accident record. The man who is slower in responding may be more cautious.” CRUDE OIL CARBURETTER. One of the most interesting of recent economising inventions is a new carburetter, capable of converting into suitable gas a mixture of GO per cent, crude oil and 40 per cent, petrol. No structural alterations are needed in the engine, the actual mileage per gallon is better than that from petrol alone, and the cost of the crude oil'is only 5d a gallon. Tho caruburetter, invented by the famous European engineer, M. Henri Claudel, is of the four-jet type, obtaining heated air from the exhaust system. It is as successful on touring cars as on trucks, involving no sacrifice of power, speed or flexibility. One six-ton truck tested with full load gave 5.G5 miles per gallon on petrol, and 7.06 on the cheaper mixture, while the figures for a threetonner were 9.8 and 1G.4 miles respectively. Tho cost in England of fitting the new carburetter is about £ls. A DELAY IN CHANGING GEARS. In “changing down the most common fault, even on the modern car, with its greatly simplified gear change, is changing too late. This may in some ways sound contrary bo the idea of fuel cconiony, but the ’ fact remains that a delayed change puts increased stress on the engine, requires greater throttle opening in consequence, and may often, on a long, steep hill, call for.a further change down. Additionally, engines are designed to run most efficiently at the higher speed, and therefore it is clear that the rate should bo kept up whenever a severe and prolonged load has to be tackled. It is evident that where a driver lias delayed his change down, so that eventually ho has to make a further change, the engine will no many more revolutions over a given distance than would be the case in which, with a good driver, the change had been made early, one change sufficing. Moreover, by over-late changing down, the average speed is lowered. SUNBURNED CARS. Did you know that your motor car can got sunburned? That may sound rather foolish, but such is the case. You probably have noticed that the finish of your car'becomes dull and loses its lustre is it is not polished at regular intervals. But do you know why? In the first place, a film of dirt accumulates on the finish and becomes baked by the heat of the engine and the rays of the sitn. Secondly, the sun, rain, heat, and cold have a weathering effect upon the finish itself. The most destructive element to the finish of the motor car is the ultra-violet ray of the sun, the same ultra-violet ray that causes sunburn when you sit on tho beach. The effects of the natural elements will wear even the hardest stone, and they also wear away the finish of your car unless that finish is properly protected. The question is how to combat this natural disintegration. The answer is: By protecting the finish of the car with an armour of wax. Perhaps you have noticed when polishing the car that tho cloth becomes stained the same colour as tho finish. This is no cause for alarm. The colouring which comes off on the cloth is made up of small particles of chalky pigment which result from erosion., and should bo removed. As long as they are allowed to remain on the finish there can bo no lustre. When removed, the natural lustre and depth of tho colour are restored. As you probably know, ordinary window glass filters out the ultra-violet rays of the sun. Polishing wax gives the same protection to the finish m the car. As long as there is a protecting film of wax over the finish, the destructive rays aro filtered out, and weathering is retarded. It is always best to apply this protecting film as soon as the car is purchased. However, polishing wax can always bo applied as long as the finish of the car is in good condition. First the finish should be thoroughly washed and cleaned with polish. Then the wax may be applied. The wax should be applied sparingly and rubbed vigorously to develop a good shine. The wax probably will not produce any brighter lustre than the polishing agent, but it will give a protecting coat which will last for months, SLUGGISH CLUTCH. While the most frequent fault encountered in the clutch mechanism of a car is tho tendency for the clutch to slip, the reverse condition occasionally occurs, especially in cars fitted with cork typo clutches running in oil. The clutch plates do not separate when the clutch pedal is depressed, and in consequence difficulty is experienced in engaging tho first gear to start the car from rest, Tho defect, of course, is one which should receive skilled attention without delay, hut pending adjustment tho owner of the car should not

attempt to engage the spinning gears by the application of brute force to the gear lever. A sticking clutch can generally be released by first adjusting the engine to the slowest possible idling speed, and then by suddenly opening the throttle so that the engine is rapidly accelerated. The burst of speed on the crankshaft and driving plate will generally release it from the driven plate, and allow the gears to be engaged without clashing. NON-SKID ROADS IN IRELAND. “ Agrijournal ” writes to ‘ Horse and Hound ’:—“ It has been recently stated in the Press that ‘ the roads prepared for motor racing in Ireland are absolutely non-skid under any conditions. Expert opinion also indicates that a perfectly non-skid road costs less money to maintain than the present slippeiy roads that exist in some districts. As one who for years has taken some interest in this'topic, the writer decided to inquire further into this matter, it is interesting to learn that the Irish roads referred to wore treated with emulsified bitumen superimposed with largo-sized clippings. Several of the racing fraternity who had used them expressed their satisfaction with the surfaces which had been provided. BROKEN SPRINGS. On holiday touring, when a heavilyladen car is forced to traverse long stretches of bad road, there is always a possibility of breaking one of the leaves in a road spring. This need cause no delay if a simple emergency device which a blacksmith will make for two or three shillings, and which can be fitted to the car in five minutes, bo carried in the tool kit. the “ splint” consists of two mild steel plates each about the thickness of a spring leaf, and four bolts on which the threads are carried the whole length of the stem. The plates should be about ;iin long and about an inch wider than the springs of the oar. Holes in which the bolts will make a loose fit are drilled through the corners of each of the plates. If a spring leaf breaks, the affected wheel should he jacked up until the spring can be forced into its normal position. Then the plates are placed along the spring above and below the break, and are tightened into position bv means of the bolts, repaired in this way, a damaged spring can safely be used throughout a long tour if one is unable to arrange for rapid, permanent repair before one s holiday ends. HOW TO STOW LUGGAGE. In stowing luggage on a car there is more to be considered than comtort for the passengers. Correct weight distribution is necessary .to avoid making the car difficult to control or liable to mechanical damage. If a rear carrier is fitted, it should be used only for light but bulky articles, such as tents. In this location the weight overhangs the rear axel, placing a heavy strain oii the rear springs and tending to reduce that on the front, with an adverse effect on steering. Heavy articles should lie placed as near the centre of the car as possible, and of the passengers, all the heavy weights should not be at the back or on one side. The running boards are a good place for heavy luggage which is too bulky to go inside, but each side should carry about' the same weight. This need not affect use of the doors, for one door on each side can be left unencumbered. ■ When adjustable shock absorbers are fitted, it will generally bo found that considerably tighter setting is an advantage when the car is heavily loaded. Control at high speeds will be materially better, and the risk of spring trouble will ho reduced. MOTOR CYCLING FIXTURES. January 28.—Sports afternoon at Brighton, February 18.—Waikouaiti Beach races. February 21.—Monthly meeting at club rooms at 8 p.m. February 26.—Social run; leave club rooms at 2 p.m. March 4..—Flying half-mile. March 25.—Night trial. CLUB NOTES AND NEWS. The first meeting of the year was held by the cycle section of the Otago Motor Club on January 17. Those present were informed that a hill climb will probably be held in the near luture, as soon as a suitable ’ hill can bo obtained. On the decision of the members the flying kilometre was changed to a flying half-mile, so that we can compete with northern clubs. It has been found that, grass track racing on the Brighton Domain would not he practicable, A number ol novelty events has been substituted, and these should prove to he entertaining. Obstacle races, motor cycle football, riding through a paper hoop, and a long jump are among the thrilling items arranged for the amusement of the public. The proceeds derived from these sources are to be handed over to the Brighton Domain Board to that motorists can have free parking on the domain. All motor cyclists are requested to he at the club rooms at 1.45 p.m. sharp to allow ample time for the ride to Brighton. A good afternoon’s sport is assured, and a dance in the evening, will provide a fitting finish to the day.

A few holiday reminiscences wore given by various members. The “ Three Musketeers’* (W. J. M'lnncs, A.J.S.; A. 0. Davies, A.J.S.; and 0. H. Bingham, lludge) gave an outline of their tour to North Cape, also a short account of mishaps. A spill in the gravel by the last two and the capsizing of a Baby Austin by the former wore some of the minor episodes encountered by the trio. The trip of 2,220 miles was thoroughly enjoyed, the roads being in good condition. The roughest road section on the whole trip was considered to bo between Waikouaiti and Dunedin. Another clubman who made a trip to Auckland was R. W. Reid (Ariel). He left for Christchurch in the rain, and had an uneventful ride right up. In Christchurch, however, he had a slight misunderstanding' with a motor car, and finally came to rest in tho gutter. A bent exhaust pipe and torn saddle bag were his worst afflictions. Ho also had a fall on the same stretch of road as the " Three Musketeers,” He happened to fall off outside a cemetery, and informs ns that some men who were near offered to attend his

obsequies. The distance covered by R. W. Reid was 1,770 miles. It was also told that 11. W. Millis (A.J.S.), who left for Queenstown, accompanied by A. E. Bingham (Rudge) and pillion passenger, had quite a run of bad luck. His misfortunes began with a puncture at Milburn, over a bank at Craigellachie, scraped a wall near Cromwell, and cracked a piston at Queenstown. Returning from Queenstown these two met another clubman in distress, A. M'Grogor. He had blown the top off his piston, and had to bo towed to Cromwell. At Clyde R. W. Millis decided to abandon his machine, which had been seizing on an average of four times every fifteen miles, and finished the remainder of the trip on the pillion of A. Bingham. . WORLD’S MOTOR CYCLE RECORD. ENGLAND TO REPLY TO GERMAN ATTEMPT. Particulars are now to hand of Ernst Home's successful attempt to regain for Germany the world’s motor cycle speed record. As surmised when the brief announcement was cabled that Homo bad in Hungary raised the record to 151.86 m.p.h., the successful ride was established at Tat, near Budapest, on the same stretch of roads as the Australian, Alan Bruce, made his world’s side car record last May. Tile machine ridden by the German crack was the same as used by Home when he twice previously lield this classic record. It is a transverse 750 c.c. straight twin cylinder 8.M.W., and the fact that the engine has a 250 c.c. smaller capacity than the official limit of capacity, makes the performance all the more noteworthy. The engine is equipped with a Zoller air compressor, which lias a supercharging effect. The continued, success of the straight twin engines ns used in the German machine provides food for thought,

from a design point of view, and no doubt ore long some British manufacturer will exploit this type of engine for speed work. ENGLISH EFFORTS. Already, steps are being taken in England to regain the record, which had previously stood to the credit of J. S. Wright‘(J.A.P.-Dunlop) at 150,7 m.p.h. The machine that probably will be used is a 1,000 c.c. twin-cylinder A.J.S. that was specially built for such a task away back in 1930, but unforeseen eventualities prevented the machine from being fully tested out. Considerable alterations are to be made to the machine by the Matchless Company; including the fitting of a supercharger. An attempt will be made on the German figures in live course of the next month or so, and a big effort made to recapture for Britain the world’s fastest speed on two wheels. TOLD AT THE WHEEL. “ You’ve been tearing about at eighty miles an hour, miss, and I'll have' to report you. What’s your name?” “Prudence.”

Vecidcnls Order of Order of per Merit, Merit > cur. Aceidcnts. in Tests. ..‘5 ... 1 ... 2 .9 ... 2 1 1.6 ... !!! !!! 6 !” 6 2.7 ... 4 ... 5 6.2 ... 5 4 6.2 ... 6 ... 8 .1.8 ... 7 ... 6 6.6 8 ... 7