MOTORDOM

Southland Times, Issue 20526, 30 June 1928, Page 16 (Supplement)

MOTORDOM

CALL FOB ACTION. The following resolutions were carried by the Marlborough Automobile Association last week: (1) That the attention of the Blenheim Borough Council be drawn to the fact that many red rear reflectors affixed to bicycles are quite useless at night time owing to their being set at an incorrect angle; that many cyclists ride after dark without lighted lamps, and that the progress of motor vehicles through the business section of Blenheim bn Friday nights is considerably impeded by the refusal of pedestrians on the streets to give them reasonable right of way; and that the council be requested to instruct its traffic inspector to enforce obedience to the law in these matters. (2) That the Marlborough and Awatere County Councils be informed that many complaints have been received by this association of the failure of cyclists and drivers of horse-drawn vehicles to display lights on country roads after dark, to the danger of themselves and of motor traffic; and that the councils be requested to take steps to compel all cycles and horse vehicles to carry lights at night. Judging from the nature of the comment that accompanied the resolutions, Marlborough is inflicted with a “happy-go-lucky” kind of populace, recking little of its own safety or that of others, and it is high time that steps were taken for a stringent application of the traffic regulations.—Evening Post. COLD WEATHER STARTING. Petrol will turn to vapour at a temperature of about 70deg. in the same way as water vaporises at 212 deg. When steam strikes a surface colder than 212 deg. it will condense and again become water. In the same way vaporised petrol will condense if coming in contact with a cold manifold after leaving the carburetter. The above is the reason why it is hard to start on a cold day. While the carburetter will do its work properly, the vapour, however, on the way to the cylinders, strikes the cold manifold and so condenses, with the result that practically nothing but air reaches the cylinders. When the engine is cranked it really travels very slowly and so the suction, and the movement of the mixture is slow, thus increasing the chance for condensation. What can we do to start weather? If, when starting, we make the mixture very rich, then, even though most of the gas condenses on the way to the cylinders, the chances are that enough will reach them to cause an explosion. The explosion will make the engine revolve fast, causing a quick suction, and a quick movement of the mixture, thus not giving the gas a chance to condense. Not only that, but because of the friction between the previously condensed gas and the fast moving air, the condensed gasoline, which is on the manifold, will be made to travel in the direction of the cylinders and so get into them, where, the temperature b?ing high from the former explosion, it will vaporise again.

To enrich the mixture when starting, sometimes the carburetter is flooded by holding down the float, but perhaps more often much of ths air is choked off by means of a choke valve. The valve is operated by a wire fastened to a rod or lever, either on the instrument board or steering column, when a self-starter is furnished, or by a wire which passes through the radiator and terminates in a small ring or hook, when the engine is cranked by hand.

Remember that the choke valve is a device for starting when the engine is cold. On a hot day, or when the engine is hot after a long run and but a few moments standing idle, it would be better not to use I the choke. When used on a hot day and • hot engine it may cause the engine to j choke; that is, become filled with so rich i a mixture that it will not start. Another cold weather device found on most cars is the “season shutter.” This should be closed in cold weather and open in warm. Few drivers pay any attention to it, but it will pay to see that it is open when the weather is warm and closed when it is cold. BEFLECTOBS FOB BIKES. The South Island Motor Union recently wrote to the Minister, of Justice (the Hon. F. J. Rolleston) urging that with a view to minimising the danger of motorists running down cyclists at night it should be compulsory for all cycles to be equipped with red reflectors, and the Minister in reply has pointed out that there may be some bicycles (particularly boys’ and girls’ machines) which are used only during the daytime, and it would hardly be fair to compel these machines to have the reflectors affixed. The Minister, however, has noted the point for consideration when the Lights on Vehicles Act comes up for amendment. By way of comment it need only be said the argument that there are bicycles which are not used at night might with equal justice be applied to motor-cars and other road vehicles. With regard to the car, regulations have been brought into effect with which every motor owner must comply no matter what the circumstances. Any bicycle is liable to be used at night, and reflectors on bicycles are essential at night. The reflector on a motor-car is not essential, yet it must be affixed. The cost of equipping a bicycle with a red reflector is a mere bagatelle, and should receive not a moment’s consideration in connection with the question of, safety. Bicycle reflectors are already compulsory in Wellington and other places.—Evening Post. OVEBCHABGING. HARMLESS IF BATTERY IS KEPT “TOPPED.” On the average small car the capacity of the dynamo and battery is usually rather under than above winter requirements. But in summer it is easy to overcharge the battery. The overcharging of a battery is not in itself harmful—so long as you keep the battery properly “stopped,” so that the liquid is about a quarter of an inch above the plates—but the act of overcharging a battery means the speedy evaporation of the liquid, so that if “topping” is not regularly cared for, the condition will soon arise when you are overcharging with partially exposed plates. And then you will commence damage. The better way is to take your car to your nearest service station and call for a test*

WHEN STARTING UP. In the old days, when every man cranked his car by hand, it was considered the topnotch of folly to crank through part of a revolution. Unless a broken arm was desired, the only safe thing to do was to take hold of the hand-crank with a will and give it at least one uninterrupted turn. Broken arms are a rarity now —the automotive type, at least—and yet many owners are violating the old rule, thereby endangering themselves in another way. Fires have been started through letting the starter-motor crank only part of a revolution. It happens this way. The engine is warm and ready for a start. Knowing this, the owner decides to step on the starter for only a second or two. There is, as a consequence a partial revolution of the crankshaft, ignition of the gas in one of the cylinders, and then a backfire. As in the old days, it pays to crank steadily and for several revolutions. This tends to keep the engine rotating in the right—and safe—direction. The momentum of the flywheel will conquer the reverse force of a weak backfire. WHY STREAMLINE IS BEST. TESTS. PROVE NATURE KNOWS HER JOB. “Because the pressure of the air from every angle must be considered, the designers of Segrave’s and Campbell’s machines had to depart from the rules established by airplane builders. It is the practice to test the air resistance of every part of an airplane in a wind tunnel, and thus to discover the shape which can be driven through the air with the least amount of energy. Wind tunnel research proved that the traditional sharp bow of a ship is scientifically wrong. Fast swimming birds and fish are correctly designed. Nature discovered long ago that the bow must have a rounded, rather blunt form, and that the tail must be fine if speed is to be attained with little effort. “This is what is meant by ‘streamlining.’ No eddies must be stirred up, if possible, and no wake should be left behind. Foaming bow waves and wakes may gladden the eye of the marine painter, but they are the visible evidences of inefficiency to the engineer. The truth is that our locomotives and steamships pay too high a price for speed in the form of engine power, and therefore fuel. Probably the Mauretania and the Twentieth Century Limited could attain their present speeds with half the fuel that they now consume if they were streamlined.” COASTING. CAN BE A HELP. AID TO EFFICIENCY. The danger of coasting has been emphasised to a point where a lot of motorists forget that it can be helpful in testing the efficiency of their cars. Coasting, for instance, will tell whether or not the wheel and other bearings are set too tight. A car can go along with such a handicap, the driver never noticing it if he happens to have a powerful engine under the bonnet and does not check up his petrol milage. Tight bearings either in the engine, transmission or rear axle will waste power at an extremely high rate. By attaining a speed of twenty miles an hour and then coasting, this can be appreciated. If there is too much drag anywhere in these three units, the car will stop within fifty yards. Make sure, however, that the tyres are up to the correct pressure and that the brakes do not drag. “ LEADED ” PETBOL. RISKS INVESTIGATED. Experts differ regarding the dangers of “leaded’ or ethyl petrol. Several American investigations have resulted in the finding that there is*no risk to health. The Daily Mail, London, conducted exhaustive trials during the first quarter of this year with a car, a motor-cycle, and a stationary engine. The finding now announced is that the tetra ethyl lead in the new petrol is risky unless carefully handled. The conclusions of Dr. M. Coplans, D. 5.0., 0.8. E., who was entrusted with part of the research are as follows: —

That lead definitely entered the system of one of the mechanics engaged in the work of dismantling the engines used in the Daily Mail road trials of ethyl petrol and the stationary engines used in the research work into exhaust gases. That the periodical medical examinations of the mechanics during their work was not only justified but would also have had to be maintained had their exposure to the action of leaded petrol been continued. Conditions in narrow streets with tall buildings in the neighbourhood of traffic blocks, or in vehicular tunnels, become a matter of the gravest concern in this densely populated country. In industrial enterprises, the removal of lead dust can only be effectively achieved by powerful driven fans or suction apparatus. In garages, tunnels, or open spaces, this dust, which is of a heavy nature, tends to hang in the atmosphere within the breathing level of man. It is known that lead dust, being of a sticky nature, will, in the presence of slight moisture, tend to adhere to the surface on which it deposits. From the ground will result surface pollution of water supplies if the dust contains compounds of a watersoluble nature. .

ELECTRICITY AND PETRQJj.

In a paper read recently before the Institution of Petroleum Technologists some interesting statements were made on the possibility of petrol fires originating from static electricity. It was remarked that if dry petrol is passed rapidly through a pipe or violently agitated static electricity is generated by the friction of particles of petrol in rubbing one against the other. In the case of numerous fires that occurred in the early dry-cleaning processes, in which benzine was agitated with silk goods, the effective remedy was to render by the addition of a small percentage of an acid salt, such as magnesium oleate. Under these conditions static electricity cannot be generated. Referring to the case of an explosion in a road tank car, experiments were made afterwards with such a tank car definitely insulated from the earth. On passing petrol through an armoured hose insulated from the car sufficient static electricity was generated to diverge the leaves of an electroscope, but any connection of the tank to earth immediately discharged the electricity. No actual discharges of any magnitude could be produced. Dampness of the rubber tyres was sufficient to break down the insulation. Fires have occurred in cases of collision and overturning which it has never been possible accurately to account for, and others no doubt will happen, the valid reasons for which it will be equally difficult to find. Modern methods of handling motor spirit through pumps by means of pipes raise this important question of static electricity generated by friction, and every result of thoughtful expert investigation must be well considered. REAR-ENGINE CAR. NEW FRENCH MACHINE. The practicability of the rear-engine car continues to occupy the attention of inventors, particularly on the continent, and the following excerpts from a description in “The Motor” of a French car of this type will be interesting to many readers. The car is an improvement upon a model brought out by the inventor, M. Jacques Gerin, about four years ago:— “The seating accommodation is for five adults. The body and chassis are in one piece and constructed of duralumin, the duralumin frame bearing a wood frame which the Weymanntype body is laid. “The battery occupies a commodious ‘box’ under the left rear seat, with an inspection door, and tools are locked under both front seats, where they can be reached without disturbing the passengers, the tool lockers openig on the sides of the body, immediately after the main body door is opened.

“The floor includes exhaust heaters and inspection doors to the brake gear. The whole design seems very neat throughout. “The car is suspended on heavy bellcrank levers, all vertical chocks from the road being turned into horizontal displacements by a set of compensated coil springs. We have tried this design on rather uneven ground, and we must say that, notwithstanding the presence of those painful solid tires, the chassis was remarkably well insulated from road shocks. This ought to be practically perfect on pneumatic tyres. “The brakes, on account of the rather unusual design of the front part of the car, are Lockhead hydraulic. “The noise of the engine is completely suppressed, although the power unit in itself is none too silent. As a matter of fact, all experienced drivers know that it is quite impossible to drive an engine: properly without hearing it. Something will therefore have to be devised to make the driver, but the driver alone, ‘hear’ his engine as it runs. But such total silence could hardly be called a fault by his fellow-passengers. “Fumes are noticeably absent from the body, as all exhaust gases are, of course, swept away at the rear. “The power unit includes a short threespeed gearbox, with central change, and an especially short transmission to the rear wheels. The reduced length of its axles goes a lond way towards the suppression of transmission noises.

“Good accommodation is provided for a small trunk inside the body. “The aerodynamical efficiency of such a car is without any possible comparison with the conventional type of car, as our readers are well aware. And this should probably be the greatest claim of M. Jacques Gerin’s new car if he did not hold in reserve a greater invention still. The engine ae a whole or the bloc-moteur, is separable from the body.

“In less than seven minutes, and by undoing twelve nuts only, the whole of the mechanical parts, engine, clutch, gear box, and transmission, still resting on the rear wheels, and thus quite easily accessible for repairs, come away and are ‘unharnessed’ from the chassis.

“They can be wheeled away into the repair shop, just as a tired horse is taken away to the stable, and replaced in seven more minutes by another power unit. The ride members of the frame are built as sliding rails to allow of such a movement. “The inventor claims the following outstanding advantages for this design. He considers, by the way, that on account of streamlining considerations, all cars in the future will have their engines at the rear, and this being quite possible, one must admit, after sitting in one of these cars, that the driving position is really delightful. The visibility from the seats is most extraordinarily increased. “A very great feeling of safety is experienced by the occupants of the car, and if, as the inventor seems to think practicable, the roof is replaced by large safety-glass panels, one would have a “sunshine saloon” which would compare very favourably with any other.”

LIGHTING-UP TIMES. On p.m. Off a.m. To-day .. .. , .. 4.38 8.2 Sunday .. . 4.39 8.2 Monday .. . 4.39 8.2 Tuesday .. . 4.40 •8.2 Wednesday . 4.41 8.2 Thursday .. 4.428.1 Friday .. . < . 4.42 8.0