MOTORING

Nelson Evening Mail, Volume LXVI, 16 February 1935, Page 3

MOTORING

PRECAUTIONS WITH FREE-. WHEEL NEED FOR HIGH CHARGING RATE Much'ink has been spilt on the subject of free,-wheeling, and there are among private owners two divergent schools of thought, says a writer in the Sydney “Herald.” One amateur declares that the free-wheel is not “worth the candle.” He is not concerned with an admitted petrol economy, which might mean a saving of a few- pounds a year, and dislikes the idea of not having the engine al-, ways at his command, and the possibility that should it stall he might iind it liard to engage positive drive when it is desired to use the engine for braking purposes. Such a critic also speaks ominously of the strain which free-wheeling imposes on the battery, which is not recharged when the car is coasting and the engine revolving at idling speed. On the other hand, its supporters assert that it is a safe and very desirable fitting, which reduces the wear and tear of the engine, conduces to a much better fuel mileage, and adds to the joys of motoring, in that one can coast for many miles during the day’s run at high speed and with great quietness. The difficulty is that both sets of arguments have much to support them. It is possible to picture a combination of circumstances in which it might be very difficult to re-engage positive drive, and an accident might result on a. steep bill; and it cannot be denied that the battery is to some extent starved when the free-wheel is habitually used. Such drawbacks are not, however, insuperable, and do not justify the condemnation of freewheeling, provided certain precautions are taken. The generator should be adjusted to give as high a charge as is permissible without endangering its windings, and it is also imperative that the engine should be so tuned that it will not stall readily, and can always be depended upon. If an attempt is made to re-engage positive drive when the car is travelling fast and the engine, perhaps unnoticed by the driver, has gone “dead,” it must either be set running again with the self-starter, or in an emergency an attempt made to crash the free-wheel into mesh, unless there is automatic Self-starting. A precaution which all users of free-wheel cars .might well observe is to resume positive drive when beginning the descent of steep hills or in any other conditions when there is the contingency that one of the lower ratios might be needed for braking purposes. If that is done the rather small element of risk is eliminated, but for general comfort and avoidance of the embarrassment of stalling the engine in crowded streets attention should be given to the setting of the idling speed, and to the ignition. It is all very well to take delight in an engine whoso idling mixture has been cut down to so fine a point | that it merely ticks over at very slow I revolutions when the foot is lifted from the accelerator; but that adjustment will not do for free-wheeling. Consider what happens when the throttle is abruptly closed. The induction manifold, at wide throttle, is well filled with an enriched mixture suited .for the engine at fast revolu-

timis, but when the accelerator is released and the butterfly valve of the carburetter closes that mixture becomes far too heavy for idling conditions, and momentarily the ignition has to deal with an excessively rich mixture which may lead to stalling if the spark plug gaps are not right, or for any other cause there is not a good spark in the cylinders. In modern engines that tendency is aggravated to some extent by the lightness of the flywheel and reciprocating parts, which are deliberately made as light as possible in order to ensure fast acceleration of the engine. If the owner is troubled by an inclination of the engine to stall when the freewheel is in use, he should first of all give heed to the idling speed, noting if the engine runs with an even beat or “hunts'’ and fires irregularly. Alter the slow speed adjustment until a reasonably brisk idling rate is secured, and keep an eye on the spark plugs, contact breaker points, and tappet clearances. ’

IGNORANCE A FATAL FAULT

DRIVER AND PEDESTRIAN

Want of knowledge in some particular direction is responsible for most of the accidents on the roads. The motorist who takes a car too fast round a. bend and collides with a vehicle proceeding on its lawful occasions in the opposite direction is ignorant of the fact that that bend had a limit beyond which it was dangerous to negotiate it—the man who takes it too fast is ignorant ‘of liis own ignorance. It is ignorance that causes the kerbshy driver on good main roads to keep well away from the kerb; he does not know where it is in relation to his ear. A little experiment would make him a better driver. Ignorance is responsible for many an accident to pedestrians, who do not know how quickly a car approaches even when it is travelling at a. low speed, or how long it takes for a pedestrian to cross a road. A little observation would provide the knowledge that might prolong their lives. It is ignorance that is responsible for so many cyclists using inferior rear reflectors and opposing the suggestion for their own safety that they should carry rear lights. They know nothing of the narrow escapes when motorists, out of courtesy to other roadfarers, have dimmed their lights only to find a cyclist with a .poor reflector in their path. Ignorance is largely due to apathy, but in some cases antipathy is responsible. Neither is permissible in modern life. Wo cannot please ourselves; wo owe something to our fel-low-men, and have responsibilities towards them. Wo are shirking those responsibilities and the duty of citizenship if we cause an accident through ignorance in any direction.

DEVELOPMENT OP DIESEL ENGINE

Returns of tlie British Ministry of Transport showing the numbers of road vehicles of different types registered for the first time in the United Kingdom give some indication of the lines upon which the use of heavy oilburning machines is developing in that country. An analysis of the figures published in “Motor Transport” shows that among the passenger-carrying class of vehicles heavy oil engines are being used to . an increasing, extent, while in the goods-carrying class of vehicle also they are being used extensively. It is stated that a reduction in fuel consumption from 200 gallons of petrol to thirty-four gallons of heavy oil on an 800-mile journey, with an average pay load of nine and a half tons, has been achieved in America by a Monovalve four-cylinder Diesel engined six-wheeler on a return journey from Portland, Oregon, to Spokane, Washington. The consumption of heavy oil works out slightly over nine and a half m.p.g. as against four m.p.g. on petrol. The performance of the Monovalve engine, which is said to develop 100 b.h.p. at 1000 r.p.m., is stated to bo satisfactory in other respects also, arid it possesses the advantage of being very easily and quickly dismantled for service maintenance. Fuel economy demonstrations like this, it is added, should create considerable interest in the Diesel, even in America, where the low cost of petrol naturally has a damping effect upon efforts to popularise the oil engine in view of its greater weight and first cost as compared with the sparkignition unit. MORE HELPFUL SUGGESTIONS These simple but useful tips are intended primarily for the new car owner—they may seem somewhat elementary but often experience causes us all t to forget the ,simple little things (writes W. Bernard, service manager, General Motors New Zealand Ltd.). Correct tyre pressures have everything to do with the good riding quality of the ear and also prevent tyre squeaks on corners. Your tyres should be maintained at correct pressure. This should be regarded as the minimum pressure and so should be a subject of weekly inspection. When the car is to be driven with a full load at high speeds it may. be advisable to increase the tyre pressure 2. to 3lb per square inch. ‘ There is one little tip in connection with the application of the handbrake, and fit- may be specially helpful to ladies. When applying the hand-brake the effort can be reduced by the application also of the footbrake. Similarly, assistance will be given in releasing the handbrake if the foot-brake is depressed at the same time. With regard to the efficiency of brakes, you will appreciate that you have a very effective brake under your right foot, but as the brake linings wear the efficiency of the brakes will decline almost imperceptibly, and so you should have them adjusted whenever you feel that the original efficiency has declined. Also, in connection with the brakes it is important to remember that a certain amount of water gefs into them when washing, and this should always be dried off when starting away after a wash. J,nst a word about the petrol cap. This may be a. quick spring-action cap and. may not be known to the' 'men at the petrol pumps, so that they may not replace it safely. ft would be wise to check this up when you take in petrol. Another important thought is that you might try your bonnes fasteners wben a raffle develops. These lionnet fasteners may not have been tightened or may work a little loose after running awhile and therefore give rise

to such a rattle; so you might save yourself a journey to the dealer if you check up these fasteners. With regard to your doors, you will be well advised to apply a little oil to the hinges and occasionally a little ordinary household or soft soap to the door jambs —soap is not so likely to cause damage to clothes. Similarly, you will find the application of a little soap to the runners of the sliding seats to be a useful form of lubrication. Let me stress a warning regarding chromium plating and correct what seems to be a misapprehension among quite a number of , car owners. It must under no circumstances be cleaned with the usual metal polishes; at the same time, water alone and a leather is insufficient. If you use a little soap with the water you will find that the stains will be removed. Then, with regard to decarbonisation. In a. general way, we do not recommend the disturbance of the engine at' any givefi miledge, but decarbonisation will, eventually become necessary and the'engine will tell you when. If pinking take place, this does not indicate that harm is being done, excepting that valve seating--may need consideration and there may be 'a tendency for valves to stick, but the main indication of carbonisation is that the performance of the ear is impaired and you will be irritated by pinking sounds.