HONOUR to the back-room boys

18th March 1955, Page 111

18th March 1955

Page 111

Page 111, 18th March 1955 — HONOUR to the back-room boys

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Part Played by Oil Technologists in Development of Motor Vehicles ; Growing Importance of Chemist in Application of Additives

WHEN considering the strideswh:ch have been made in the development of the commercial vehicle during the past 50 years, the tremendous contribution made by the leading oil companies is apt to be overlooked. Yet it is probably true that had it not been for the petroleum technologist, the commercial . vehicle could never have reached its present stage of efficiency.

Today, a particular brand of. lubricating oil is more or less accepted

without question. This alone shows the confidence which the user has learnt to placein the people whose job it is to provide protection for.all the moving parts in a valuable piece of mechanism.

It is not always appreciated, however, that behind the production of a particular lubricant or type of fuel have gone yearsOf research, possibly accompanied by the expenditure of vast sums of money on the specialized plant called for in refining and other processes.

Reducing Viscosity

There is a feature of all quality lubricating oils available today that anyone who is able to go back, say, 30 years will recognize as being different from the lubricants then in common use. It is their viscosity, or fluidity. "1 he quality of a lubricating oil was, at one time, frequently judged by its apparent " body." The average user thought that if it possessed this quality it was good.

Such reasoning was and is, of course, fallacious, but when the oil companies introduced thinner oils of vastly improved quality, users were at once concerned about the drop in oilpressure readings, and all kinds of trouble which had no connection with the use of such oils were attributed to The fact was, of course, that many of the constituents that made the oil thick were undesirable. Far from contributing to the lubricating quality of the oil they had the reverse effect by promoting sluggish circulation, creating excessive fluid friction and making starting more difficult. They also showed an increased tendency to form carbon. •

Thinner But Better

The process of removing the heavy ends, as they are called, has engaged the attention of oil technologists for many years, with the result that today most good-quality oils, although apparently having little body, possess a lubricating value and a safely factor far exceeding those possessed by engine lubricants that were available 30 years ago.

Whilst these remarks are not intended to be a direct reference to the lowviscosity oils which are now gaining favour with a number of large operators, it would be appropriate, at this point, to bring them into the picture.

The introduction of these unusually thin oils in the order of S.A.E.5W and S.A.E.10W met with mixed feelings among operators. Users were naturally apprehensive of the ability of such thin lubricants to provide the necessary protection for cylinder bores, main and big-end bearings, and other rubbing surfaces against unduly rapid wear.

It has since been proved that not only are these types of oil capable of keeping wear at a lower level, but they have also been directly responsible for a big reduction in fuel consumption; in fact, they have made the biggest single contribution to this desirable result.

Although the oil technologist has played a leading part in their development, credit must also be given to the chemist who, working in close liaison with the oil companies, has made the

use of thin oils possible. It is the chemist who-is responsible for the additives which impart the ability to with stand degrees of loading which could not be resisted by the base oil without rupture of the essential film.

One of the most important developments in connection with both lubricating oils and fuel is concerned with the use of such additives.

A type of oil whicluhas been in fairly general use for many years is that having a detergent additive. This has proved particularly valuable in the case of oil engines, which depend so largely on ring-seal for their efficiency. Since detergent oils have become generally available, much of the trouble in oil engines associated with sticking piston rings has been eliminated, whilst the general internal cleanliness maintained by these engines is particularly notable.

The introduction of the hypoid gear, with its high unit pressure and high sliding velocity, presented the oil technologist with a new' problem. Existing gear lubricants• did not provide the requisite factor of safety. Here, again, the use of additives has provided a satisfactory lubricant, and one which will operate at temperatures up to 145° C. Developments are, however, still proceeding and it is likely that hypoid-gear oils will become available that will give safe protection up to a temperature as high as 1657C.

Self-changing gears of the hydromatic type, epicyclic gearboxes, and even hydraulic shock absorbers, have all presented tivir special problems for solution by the technical staffs of the oil companies.

Were it possible to select an oil for ally given duty purely on its physical characteristics, many lubrication problems would be simplified, but unfortunately this does not work out in practice. The major oil companies certainly maintain extensive laboratories, in which they have facilities for conducting and evaluating results of tests of all types of components. Whilst such tests are valuable, it does not always follow that a lubricant which has given satisfactory results under controlled conditions on the bench will give similar satisfaction in normal service.

Stilt Learning

Correct lubrication has developed into a science, but not an exact science, and no petroleum technologist would assert that he knew all there was to learn about oil. Each year brings with it fresh lubrication problems and, in seeking their solution, the oil technician will undoubtedly have occasion to call in the aid of the chemist to an increasing extent.

Equally extensive has been the research devoted to the production of fuel. So far as the petrol engine is concerned, compression ratios have steadily increased during the past' few years, with a decided improvement in the power output and efficiency of this type of unit.

The limit to the compression ratio which can be adopted is governed largely by the non-detonating nature of the fuel available. According to pull

fished statistics, 8 per cent, of petrol engines in 1953 had compression ratios of 7.5 to I or over, whilst in 1954 the figure rose to 27 per cent.

Anti-knock Spirit It is significant that it was not until February, 1953, that branded fuels again became available after a long period of the supply of pool spirit. With the return of competition between the oil companies, there was an immediate release of motor spirit having anti-knock qualities. This availability of improved fuel is clearly indicated by the almost fourfold increase in high-compression-ratio engines in the first year of such fuels being available.

So extravagant were the claims made for these new fuels that a section of the public was inclined to doubt their veracity. Be this as it may, there is little doubt that the oil companies arc right on top with the range of fuels which they have developed to meet the needs of the modern high-compression petrol engine as well as those of the compression-ignition unit.--P.G.T.