MOTORS and MOTORING

Dominion, Volume 25, Issue 94, 15 January 1932, Page 15

MOTORS and MOTORING

By

"SPARE WHEEL”

For absolute driving efficiency, tbe car must be kept in safe, mechanical condition.

When driving in wet weather, high speeds should be avoided, and on wet nights it is much harder to distinguish objects, such as pedestrians crossing the road, therefore greater care should be exercised.

' Many novices make the mistake of holding the wheel in a tight grip. This practice does not make for efficiency and only has the effect of producing fatigue. It is only necessary to retain a light grasp/in order to keep the car on a straight course.

Four-wheel brakes have not changed the truth that the better treaded tires belong on the rear. On most occasions these wheels take the heavier part of the braking force.'

Many owners secure their spare tires to the carrier by means of a lock and chain. Frequently the lock becomes badly rusted. In that condition it is an easy prey to the thief’s well-directed hammer blow and, further, it is annoyingly difficult to open by key ■when the occasion finally demands.

PARKING THE CAR Skill in the art of parking is absolutely necessary in these days of restricted parking areas, where every inch counts. A driver also needs to be a good reverser, especially when parking between two cars where a space only slightly more than a car’s length is available. It is advisable under such circumstances to steer as close as possible level with the forward car, then, on a sharp left-hand lock, reverse until you are two-thirds into position. Swing the steering wheel smartly to the opposite lock and complete the manoeuvre. This will bring you parallel with the kerb. In wide thoroughfares it is easier, both in parking and moving out, to place the car on an angle to the kerb. On all occasions it is necessary to park so that traffic will not be impeded. AVOID OVER-OILING Although it is essential to ensure adequate lubrication for the engine, avoid, if possible, over-oiling. Not only is this wasteful of lubricant, but it causes trouble by fouling the plugs and valves and choking the silencer, in addition to creating a considerable amount of smoke in the exhaust.

MOTOR OILS Importance of Quality Part 11. The following is the second of a series of three articles dealing with the quality of motor oils. The previous article dealt with the importance of accurate control of basic materials, refining processes and blending in the production of high-grade motor oils. It was pointed out that such control cannot be given unless tbe Supplying oil company possesses a technical staff who have training and facilities to watch the quality of oil from crude to car engine. The following notes dealing with specific requirements of a motor oil would indicate how each characteristic or function must be carefully studied and not left to guesswork. Tbe primary work that a motor cylin-, der oil is called upon to carry out is to reduce friction and dissipate heat. The oil also acts as a sealing medium between piston and cylinder walls to enable the necessary compression to be given to the combustible gases. The friction-reducing properties of an internal combustion engine oil are influenced by: (a) The inherent quality of the oil itself; (b) viscosity; (c) contamination through carbon formation; (d) sludge formation; (e) contamination by dust, water, etc. The essential properties of high-grade motor oils are: (a) Maximum fric-tion-reducing properties; (b) minimum carbonisation; (c) low sluge tendencies; (d) absolute purity of the oil itself. This article will be confined to sections (a) and (b). / Solid friction, resulting from metal to . metal contact when one surface moves over another, can be substituted by fluid friction due to a film of oil being placed between the rubbing surfaces.

It is impossible to completely overcome friction in a motor engine. However, the friction .can be considerably reduced due to the lower friction between oil films as against metal surfaces in contact. .When we exclude the influences of contaminating agents such as dust, metal, water, etc., it can be said that the best lubrication will be given by: (a) the oil which in Itself possesses maximum friction-reducing properties, and (b) the lightest bodied oil than can be used in a particular system. 7 The term “oiliness” applied to lubricating oils is quite a common one, and, while it is not possible to definitely express “oiliness” as we can viscosity, flashpoint, cold test, etc., it is well established that certain lubricating oils have greater "oiliness” or great friction-reducing properties than others.

It is here that the initial quality of the basic material and refining treatments are made evident. Low quality, poorly refined oils are deficient in lubricating properties and have a low “oiliness,” and will be responsible for excessive wear taking place. Viscosity, or body, is the other important factor influencing friction reduction. Viscosity is’ a method of expressing comparative thickness or thinness of various oils. All mineral oils have a tendency to increase in viscosity with drop in temperature and to thin down or have lower viscosities at increased temperatures. The degree to which this variation in viscosity takes place is governed by the quality of the initial lubricating oils used and the manner in which they are blended. In view of the friction which actually exists when one film of oil is moved over another, it is essential that to ob-' tain the maximum power output from the engine the lightest viscosity oil that will suit the particular system be used. The chief object Of blending motor oils is to ensure that suitable viscosities are provided to meeting the operating conditions met with. Seeing that engines must be started up when external temperatures are very low, and as the same oil must operate when considerable heat has been developed,, a wide range of conditions must be catered for. It is with the. object of meeting these variations in operating conditions influenced by temperature and engine design that every oil company ma'rkets a range of motor oils, as it is not possible to use one oil to suit all lubricating systems. The actual number of grades and qualities marketed follows on a considerable amount of research. It is essential that the grades be kept uniform, and it is here that control laboratories are necessary to supervise blending operations. , Research has shown that the maximum amount of friction wear in a motor car takes place during the early stages of running, due to the fact that it is difficult for oil to reach all friction points. Heavy sluggish oils will not give’the necessary lubrication until the engine has been running some time, and during this period undue wear is taking place. These heavy oils also result in loss of power, due to the excessive'internal friction of the oil itself. A range of high quality motor oils suitable for various types of lubricating systems can only be produced by the correct blending of suitable basic materials to ensure that the viscosity or body of the oil is such that, irrespective of intense heat or cold, a durable film of oil is keeping apart all metal to metal bearing surfaces. . Motorists, therefore, should rely on purchasing oils from concerns who are in a position to ensure every lubricating requirement being catered for. Excessive wear and resultant maintenance charges are brought about by using oils deficient in lubricating qualities. Therefore —do not take a risk. EXHAUST GASES Danger of Carbon Monoxide There is always a possible danger arising from exhaust gases, which may carry carbon-monoxide (a potently poisonous gas) into the immediate atmosphere as one of the results of combustion. Therefore, when running your engine for any purpose in your garage, see that all doors and windows are open so that fresh air may circulate freely in the building. If yours be a closed car, and has been left standing with the engine running, thorough ventilation should be provided, as some of the heated carbonmonoxide from the exhaust may rise and enter through the floor of the cai. When the car is in motion the exhaust gases are discharged without the slightest danger. In the event of anyone being overcome bv inhalation of these fumes, immediately proceed to apply resuscitation methods as for the apparently drowned. A due observance of these rules and precautions will assist in eliminating the element of danger and so remove any cause for anxiety when handling petrol or working in the home garage.'

GUIDE TO SIZE Classifying by Wheelbase Owing to the British method of describing cars by their somewhat artificial horse-power rating, many motorists tend to lose sight of the fact that the wheelbase is by far the most useful guide to the, size, weight, and body Space of an. .automobile. It is a pity that this invaluable dimension should be neglected, particularly in view of the fact that the modern tendency is to provide a choice of engines in chassis which otherwise are well-nigh identical. For example, we may take a number of medium-sized cars, all with a wheelbase of between Oft. 6in. and 10ft., the ratings of which may vary, according to engine size, between limits as far apart as 14 h.p. and 24 h.p. The body and the, general size of the car is practically the same in each case, yet people automatically tend to think of a 24 h.p. car as necessarily being much bigger than al4 h.p.' car. Naturally the rating is useful as giving an idea of the size and power of the engine and as showing the tax which is payable, but it should be limited to these purposes and should not' be taken as a guide to car dimensions. Another advantage of getting to know the wheelbase is that it gives a good idea of the overall length of the car, which Is often very important when garage accommodation is limited. Similarly, although to a lesser degree, the track is a useful dimension to keep in mind, as it is a measure of tbe overall width and also gives an idea of the internal dimensions of the coachwork. The wheelbase and track are invariably stated in the manufacturers’ specifications, and the following average figures will show how they vary in the car types which are most popular nowadays. Commencing with the “baby cars, which provide full scale /seating for two people and emergency seating for additional passengers, it will be found that wheelbases vary between 6ft. Sin, and 7ft., while the track is usually 3ift. or slightly less. These dimensions indicate the minimum size to which a mo-tor-car can . usefully be built Next comes the new class of economy car in which full-scale four-seater coachwork is ingeniously fitted to a chassis of small dimensions, the minimum wheelbase employed being 7ft. 6in and the maximum'nearly Bft. Here, again, the track is usually limited to 33ft. Proceeding in order of size, we oome to- a class which embraces the 10 h.p. four-cylinder models and small sixcylinder cars rated at about 12 h.p. In each case, the body-work is of much the same size, providing adequate room for four people but capable of carrying five at a pinch. The wheelbases employed range from Bft. to Oft. and the track is usually about 4ft. Naturally, a six-cylinder engine is a few inches longer than the four-cylinder type, so that for the same body space the wheelbase of a “Six” must be proportionately increased.

Before going farther we may mention that the overall lengths of tbe cars we have described are usually found to be from 3ft. to 4}ft longer than the wheelbase; while the overall width may be taken as being nearly Ift. greater than the track in almost all cases. We now come to a car class which provides somewhat roomier body-work suitable for carrying three people in reasonable comfort on the rear seat. Here a great variety of engine powers is available ranging between limits of about 15 h.p. and 25 h.p. The highpowered examples are naturally mostly of trans-Atlantic origin, but there is a growing number of British cars rated as high as 20 h.p. which appeal to those who-appreciate a power-weight ratio sufficiently to pay a heavier tax for this luxury. The wheelbase of this class of vehicle varies between 91ft. and 10ft„ sand the track is usually the standard dimension of 4ft. Bin.; there are, however, examples of the use of slightly narrower tracks.

The overall length may be anything from 4ft. to sJft. longer than the wheelbase, according to the space occupied by projections, such as bumpers, luggage grids, and spare wheels. The width, as in smaller cars, js usually about Ift. greater than the track. Turning to. larger cars usually rated at over 24 h.p., we find that the wheelbases range from 10ft. up to something in the neighbourhood of 13ft. for the very longest and most costly types. Generally speaking, to carry sevenseater coachwork with proper space for occasional seats a wheelbase not shorter than 10ft. 6in. is necessary. In this class a 4ft. Bin. track was at one time universal, but nowadays, in order to provide still wider bodies, many makers are using tracks of sft., or even greater dimensions. The overall lengths of these cars are usually between 44ft. and 51ft greater than the wheelbases, and the widths are from Ift. to 14ft. greater than the track. ' In conclusion, it may be mentioned that manufacturers try to use a moderate wheelbase and track for the reason that by so doing weight and cost are reduced. i “RUNNING-IN” Care of New Car Most manufacturers and agents specifically warn the owner not to run a new car faster than 20 to 25 miles per hour in top gear for the first 500 miles. It is possible to spoil a good car and materially shorten its useful life if the warning is ignored. Another point that must be strictly adhered to is that only the highest grade oil of scientifically correct body should be used from the day the car is put on the road. The manufacturer turns out the car as perfect as is humanly possible, but if the moving parts, such as pistons, cylinder walls, etc., were examined under a microscope, small irregularities on their surfaces would be seen. Only by fhe gentle rubbing of one part over another in the .presence of a high-grade lubricant can the roughness be removed, and a glass-like finish be imparted to the moving surfaces. It is at this period of a new car’s life that the engine oil must bo drained at more frequent intervals than later, when the car has been thoroughly run-in.

Small particles of metal are removed by the running-in process- and circulate with the oil. This abrasive material must be removed as it is produced, so it is wise economy to drain the crankcase after the first 250 miles. Subsequent drainings should be carried out at periods of 1000 miles in summer and 500 miles in winter. It is well to drain while the engine is still warm, for then most of the sediment, in suspension in the used oil, will be carried away. Knowledge of the mechanical details will help every car owner considerably In achieving efficiency in driving, and will prolong the life of his car by enabling him to avoid placing undue strain or wear on the car’s mechanism. Time spent in a close, study of the controls will amply repay the motorist.

PRIVATE GARAGES Necessary Equipment The thoughtful motorist provides many items of equipment in the home garage in order to save himself vexatious delays when the -need arises for a new spark plug, a spare bulb or an inner tube, etc. Lockers to contain spares/ polishes, etc., should be installed, and also a strong bench where many jobs of a simple nature may be carried out. Among the stores should be spare tires, tubes, light bulbs, spark plugs, together with washing, cleaning, and polishing equipment, such as chamois leather, good quality sponges, and a wire brush for the underneath parts of fenders and chassis. Other useful articles that should be in every home garage 'are —a reliable hydrometer for battery testing, a thickness gauge for checking tbe gaps of spark plugs, contact-breaker and tappet clearances, and a spark plug ignition tester. BRAKE SPRINGS > There are many springs associated with the brakes of a car, semi-exposed and some hidden from view. With one or two exceptions, however, brake springs need no attention; nevertheles, they will not function correctly if they are neglected, or rather if they are called upon to do impossibilities arising from neglected lubrication of the brake-shafts and joints. Thus, there arc the brake-shoe springs that pull the shoes away from the drums, and keep them thus, when the brake pedal or lever is released. These springs cannot always or fully overcome the frictional resistance of unlubricated and rusty shaft bearings. Spring-time work on springs should therefore include thorough lubrication of all brake-shaft bearings and joints. To make sure that they all work freely, let the lever movements be watched by one person while another operates the pedal and hand-lever. Do not use the grease or oilgun perfunctorily; make sure that the liibrlcant is really going into the bearings. The springs on brake adjusters should be examined to make certain that they are functioning freely. They are intended to Aock the adjuster automatically and prevent the adjustment from slackening back. Some oil on the adjuster details and the springs themselves will assist the latter to do their duty.

There is a spring on the hand-brake trigger/, make sure that this is really effective in holding the pawl in engage--, ment with the toothed quadrant. A weakened or broken spring might allow the lever to slip to the “off” position while the car was unattended; and if that happened on a hill—well, the possibilities for barm are obvious.

The wiring or electrical system requires little attention beyond seeing that all wires are thoroughly insulated, and that they do not come in contact with any oil or grease, for these substances quickly destroy the rubber insulation ou the wires, which may become short circuited. The battery or accumulator must- have its plates covered with liquid at all times.

BREAKING IN TIRES It may seem reasonable that the engine should be broken in carefully, but the average motorist never would think of breaking in the tires. However, there is some merit in that idea. If a new tire is purchased, instead of putting it on the spare rim put it into service right away.,, It will make the tire more pliable in case it ever has to be removed from.the rim, and, further than this, the discoloration the tire acquires will help protect it from the sun’s rays.

CHANGE DOWN EARLY Do not hang on to top gear too long; when ascending a long hill a far better climb will be made if you change down from top to third or second quite early before the car has lost way. By so doing you will be able to maintain the engine revs., which, if once lost, will involve a slow and tedious ascent. The same applies in traffic; do not hang on to top if the engine is not flexible, and ensure also a better get-away when the opportunity presents itself. WOODS’ GREAT PEPPERMINT CURE —For Children's Hacking Cough.—Advt,