HIGH-SPEED OIL ENGINE

Hawke's Bay Tribune, Volume XXIII, Issue 102, 11 April 1933, Page 4

HIGH-SPEED OIL ENGINE

IMPROVEMENTS IN INJECTION. In many parts of the world experimental and laboratory staffs of automobile manufacturers are keenly searching for a more efficient engine than the orthodox petrol power-unit, and the opinion appears to be gaining ground that radical alterations will be made soon to the conventional motor engine. The fact that the modern power unit only delivers about 22 per cent, of the thermal efficiency of the fuel it consumes is m itself a great incentive to designers who are working towards greater engine efficiency. Probably never in the histor of the automobile have so many keen brains been concentrating on this problem, and judging by the ninny promising inventions that have recently been announced in various parts of the world, there appears to be at least a reasonable chance that something worth while will soon be evolved. Tho perfection of a high-speed fuel oil engine for use on cars would increase thermal efficiency by 50 per cent., and it is in this direction that many experts are working. DRIVERS’ INVENTION. One of the latest reports of advancement in the evolution of such an engine, claimed to be suitable for use in motor-cars, comes from France, where two well-known English racing drivers, Mr W. Marchant and LieutenantColonel R. Stewart, are reported to have produced a high-speed oil engine of 1000 c.c. capacity that works at 5000 revolutions a minute, and can attain a very much higher speed. The limiting factor to high engine speed in the compression-ignition power unit lies largely in the oil injection apparatus. In the Marchant-Stewart engine an electro-magnetic system is used, in which the action of the injector is controlled by an ordinary type of distributor such as that used in the ignition system of a petrol engine. The engine has many original features. There are three cylinders; the central one, which is of larger capacity than the other two, acts as an air pump. This cylinder has a rotary air inlet valve, and the other two cylinders have ordinary overhead valves of the poppet type. The engine, which is neat and compact, has a very high power-weight ratio, and is stated to be a most promising development.