DIESEL ENGINE TYPES.

New Zealand Herald, Volume LXVII, Issue 20596, 21 June 1930, Page 36 (Supplement)

DIESEL ENGINE TYPES.

•PRO G RESS IN AMERICA. .' OPERATION; ON CRUDE OIL,' Within the next year, o?. two Diesel engines will bo very much more prominent in America for every form of automotive transportation . Chan at present. Diesel engines, experimentally at least, can hardly bo in tho majority within that 'time, but thoy will not be difficult to find. This prediction is based on the groat progress made by this type of powor plant within the past year. During tho latter part of March, 1930, a speed mark of 78.247 m.p.h, was set by a Diesel-equipped passenger car at Daytona Beach, Florida. This car is tho machine turned out by the C. L. Cummins Engine Company, of Columbus, Indiana. It is the same vehicle which, in January, was driven from Indianapolis to the New York Automobile Show on about six shillings' worth of crude oil fuel. This company has been making these engines for 12 years for marine and stationary use, and has been experimenting on trucks, buses, tractors and shovel machinery because of the extremely low cost of fuel and the simplicity of operation, Sceptics said tho Diesel was not flexible enough for some of these uses, and, to prove that they were wrong, C. L. Cummins purchased. (l 1925 passenger car chassis and put-into it tho standard four-cylinder Diesel engino, which mado the speed record already mentioned. The only chassis changes necessary for this test run were tho removal of tho old engine and a chango in tho gear ratio from 4.69 to 1 up to 2£ to 1, for tlie Diesel is a powerful, low-speed motor. The -car was driven on its first trip a distance of 2780 miles, and the total fuel cost was about 30 shillings for the 102 gallons of fuel used. Diesel Aero Engine. Details have jusfc been released concerning the new Packard Diesel aircraft engine, developed by tho Packard Motorcar Company', of Detroit. This machine is of tho "radial, air-cooled typo, has nine cylinders, with a bore'of 4 3-6 in., and a stroke of 6in., giving a displacement !of approximately 980 cubic inches. The engino is rated 225 h.p. at 1900 x.p.m., ahd weighs 5101b., or 2.261b. per rated horsepower. The fuel found most satisfactory is domestic furnace oil, as used in residential heating plants, and which' costs about nino cents per gallon. Details 0! the Design. An important feature of the engine is that only one valve is provided per cylinder, this being mounted in the head and. operated by a rocker and push-rod. The single valve serves to admit air on the induction stroke, and to release the. burnt gases on the exhaust stroke. The fuel is burnt by tho heat developed in compressing the air, tho compression ratio being 16* to 1. Fuel is injected at a pressure of 60001b. per square inch. As the pressures reached in the cylinders are very much higher than those which obtain in a-petrol engine of the same power, great ingenuity was needed to reduce tho weight to a figure of 2ilb. per horse-power. For example, in order to avoid high stresses, which would have .necessitated a much heavier, crankshaft, the propeller bos 3 has a certain amount of float and is driven through rubber blocks. The crankcase weighs only 341b., and is relieved of stress to a considerable extent by the use of alloy steel hoops, which encircle the cylinder flanges. Interest in the Diesel engine in America is spreading rapidly. It has been tried on trucks, buses, and now on passenger cars. In every case it; has proved its merit beyond any question of • reasonable doubt. Just how soon Diesels will como into more or less' general usage depends first on public demand- for; greater economy, SOUTHLAND MOTORING; A satisfactory < year's work is-recorded, in the annual report of the Southland Motor Association, which was issued re-., cently. . The balance in the revenue' .account shows an • increase of £122/ according to the report, which states that 1 one of the largest items of expenditure during the year was in connection with the construction of an up-to-date building for the' Invercargill motorists' camping ground for the nse of members of the association and affiliated bodies. The report states that the membership shows a largo increase over last year's figures. The membership now stands at 2031, but while tho progress of tho association has been fairly rapid, it is pointed out that there are still a number of Southland motorists who have not yet joined the Association. Particular attention has been given to tho matter of road signs, and the report pays a tribute to the work of the particular committee controling that section of the Association's work. Tho report states that with the erection of direction, danger and colour route plate signs, Southland roads are considered by many to be the most completely sign-posted of any district roads in the South Island. During the past nearly- 200 sign boards were authorised for erection. Reference is also made to the colour route guides published by the Association during the year. A copy was issued to every member, and many congratulatory letters have been received by the Association on its publishing such a comprehensive and valuable map.