OIL AND FUEL.

Southland Times, Issue 19291, 9 July 1924, Page 9

OIL AND FUEL.

WHAT DO THEY COST YOU? How many owner-drivers can state definitely and authoritatively the actual number of miles which their care will run on one gallon of fuel? As a general rule, the most rough-and-ready -calculations are utilised in order to give average consumption, to which the proud owner almost invariably adds a mile or two, in order to make the figure look slightly better, and because he feels that, if he roally tried, he could cut his consumption down to the stated amount. Accurate running figures are, however, of rather greater utility than as a means of bragging to one’s friends,. for they are a very valuable check on the mechanical condition of the car throughout. For in stance, if it be found by accurate measurement that on a certain road and under certain conditions the car will cover 37 miles to the gallon, an inquiry obviously is needed should it be discovered at a later date that under the same conditions a consumption of only 30 m.p.g. is being obtained. HOW MECHANICAL EFFICIENCY COUNTS. The same argument exactly applies to engine oil, but in this case excessive consumption will point more closely to some engine derangement rather than to a fault in the chassis. Generally speaking, the owner-driver reckons that petrol consumption is governed purely by the size of main and pilot jets fitted to the carburettor. Thus, one will often hear a remark such as: — “On a 90-main and 45-pilot my bus will do 37, but I can get much greater by fitting smaller jets.” Utterances like this show unmistakably that the speaker evidently does not reckon with such important influences as those which are introduced by condition of road surface, direction of wind, degree of tyre inflation, and last, but not least, the mechanical efficiency of the whole chassis. The last-named point is of prime importance, and is illustrated by the following incident. After a matter of 12,000 miles, it became necessary to renew the brake shoes, which were of the internalexpanding type, on a certain car, and after the job had been completed the car appeared to run just as well as previously. A very slight laziness on hills was put down to unusual atmospheric conditions caused by the heat wave; but it was not until a careful check of petrol consumption was made that it was discovered that a marked increase in petrol consumption had taken place. As the brakes were functioning perfectly, no suspicion was cast upon them, the old adage, “out of sight out of mind” being truly illustrated. A number of detail inquiries were instituted, adjustments made, and further consumption tests carried out, but all with the same result. ACCURATE FIGURES NECESSARY.

A shower of rain provided a clue, however, for at the conclusion of a run it was noticed that the brake drums were steaming slightly, duo to the evaporation, of water which had been thrown up on to them from the road surface. The car vzas then pushed along the level in neutral, and the suspicion confirmed, for it did not run nearly so easily as was its wont. The brake adjustment was immediately tackled, the shoes being eased off slightly, when, with gratification, it was noticed that the petrol consumption had returned to its original excellent level. Haphazard methods of measuring are useless. To obtain accurate data upon which to work, the actual consumption to the mile must be ascertained, and as it entails very little more trouble it is well worth while. Every journey starts from a garage, the floor of which is usually level, and this should be made the measuring ground. There is no need to rig up special tanks or even proper recording instruments, but both provide greater accuracy, and will be dealt with later. In the first instance, however, a rougher test, but one which will yield accurate figures, may be embarked upon. Before leaving the garage, the tank must be filled to a pre determined level, which should not be too high up the filler neck, otherwise slight wastage through “slopping over” may result, but to a height which will preclude this possibility. The level may be fixed and identified by using a gauge stick, and it is just as well in the first place to make sure that the petrol tap and the pipe connections do not leak. A journey, not shorter than 50 miles in length should then be undertaken—needless to say it may coincide with any journey, either for business or pleasure, which the driver has in view, and when the car is once more in the garage it should be manoeuvred so that it rests on the same floor area as when the tank was filled. The level of the fuel must then be restored to its former height, the quantity added being, carefully noted by using a properly graduated measure. A simple sum in arithmetic will then give the desired result, which has not only been obtained with the maximum ease, but is also accurate. CHECKING OIL CONSUMPTION.

The same procedure exactly can be carried out with regard to engine oil, but even more care is required in filling up, as, owing to capillary attraction, the dipper rod is liable to give an erroneous reading. This rod must be withdrawn, carefully wiped, re-inserted and withdrawn quickly once more on each occasion when it is desired to check the level. Even a slight inaccuracy will make a big difference to the cornftimption figure, in view of the greater number of miles, bulk for bulk, that a car will run on, say, half a gallon of oil compared with half a gallon of petrol. Oil and fuel consumption judged side by side give a very fine indication of the general tune of a car; thus, if, as in the incidents quoted above, binding brake drums are increasing the petrol consumption, it is more than probable that the oil consumption will also increase, due to the heavier labours imposed upon the engine. Should it be discovered that the oil consumption is higher, whereas the fuel consumption is the same, then the symptoms point to an escape of oil due to worn bearings, “sloppy” pistons and rings, or a leaking joint, say, at the sump or in the valve cover. The last-named, incidentally, is a prolific cause of oil wastage, and care should be taken to see that the felt lining, which is usually fitted is making proper contact with the cylinder block, and also that the thumb screws are tight. Vice versa, if it be found that the fuel consumption has gone up, whereas the oil consumption is the same, the owner instinctively should go over the various piping connections, check the carburettor for intermittent flooding, and examine the tank for any slight leak which may have developed. SPECIAL MEASURING DEVICES. Turning now to the use of special measuring devices, the most simple form is a can which can be connected to a lamp bracket, and connected to the carburettor by a length of flexible piping. So much trouble having been involved, greater care can be exercised in the road run, and the tank should be fitted up on the highway opposite a milestone, from which point the running test will begin. It will be necessary to disconnect the ordinary fuel supply, and this, incidentally, will facilitate the draining of the float chamber. The flexible pipe having been coupled up, an amount of fuel which can be decided upon by the driver, but is preferably not more than a quart, can be poured into the temporary tank, and the car should be driven off as quickly as possible after the engine has been started. The number of miles actually run by the car before the engine peters out can be checked by speedometer, and also by the roadside milestones; when it is desired, the vehicle can be turned round, and a similar test carried out in the opposite direction, an average being struck between the two consumptions. An even more accurate test, the progression of which can be carried out under the eye of the driver* is possible if

graduated glass meter be used; and although comparatively expensive, they can be purchased, or, if the owner-driver is lucky, borrowed from a friend. If it be desired to check the fuel consumption, a mileage meter can be installed on the dash, where by turning a tap, a test can be instituted anywhere and at any time - LIQUID RUBBER. HIE LATEST DEVELOPMENT. Liquid rubber is a good deal like cow’s milk—it is white in appearance and carries rubber particles in suspension. A single average rubber tree in a year’s tapping gives about three pounds of rubber. The liquid rubber is called “latex” in the rubber industry as well as in the scientific world. Latex ib shipped to this country just as it comes from the trees, except for the addition of a slight quantity of preservative to keep it from coagulating in transit. Practically the entire production of the great plantations of the United States Rubber Company in Sumatra and the Malay Peninsula is now shipped to the United States as latex or in the form of “sprayed rubber.” Sprayed rubber is coagulated in the manner that its name implies, by a remarkable new mechanical process. It is very dry and has strength and ageing qualities never before equalled in commercial rubber. To care for its needs the United States Rubber Company takes not only the entire yield of its own plantations, but has contracted also for the entire latex production of a number of other large estates in both Sumatra and Malaya. As an administrative measure, the United States Rubber Company has established a “Process Department,” which takes over the latex from the plantations and manufactures it into sprayed rubber at its big Eastern spray plants or ships it to America in latex form. The new methods of handling the latex have quite revolutionised the routine of plantation activities. Scattered about the company’s great esetates in Sumatra are nearly fifty receiving stations where the latex is weighed and run into temporary storage tanks. A narrow gauge steam railway transports the latex from the receiving stations to the factory, if it is to be used for sprayed rubber. If the latex is to be shipped in liquid form to America, it is taken directly by railroad from the receiving stations to the seaboard, where it is stored in big reservoirs. On plantations selling their production to the company, the latex is conveyed by railroad or motor tanks to the seaboard. The chief ports of shipment are Belawan, Sumatra and Port Swettenham in the Federated Malay States, where the company maintains besides adequate storage tanks a fleet of tank lighters. The problem of procuring adequate facilities for transporting latex to the United States was at first a real one. By experimenting with small quantities in special containers, the company first established the feasibility of importing the rubber into the United States in liquid form. Then steamship lines were approached with the suggestion that the ballast and oil tanks be thoroughly cleaned and that the latex be carried in the tanks as cargo. There was considerable skepticism at first on the part of the steamship companies, but when experimental cargoes brought no unsatisfactory results, shipping companies began to compete for the business, and now four lines are equipped to carry cargoes. When the ships arrive at an American port, the latex is pumped by the company’s own equipment into railroad tank cars of the sort commonly used for the transportation of petroleum. A barge carries the tank cars alongside the ship, and the operation of transferring the latex to the cars is carried out with dispatch by a specially trained crew of workmen. The tank cars transport the latex by rail to the various factories where latex is used.