Passing Comments
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American. Forecasts Engine Design
ARESEARCH engineer of the Ethyl Corp. recently made a prophecy concerning the attributes which. were to be expected in 1960 from heavy-duty vehicle engines. He believed that 0.5 b.h.p. Per cu. in. of piston displacement would be given by petrol engines, whilst the corresponding figure for oil engines would be 0.4 b.h.p. The compression ratio with petrol would be 7.5 to 1 or higher, whilst oil engines would give an iinprovement of 20 Per pent in economy. The durability of engines would be greater and both types would be lighter on both the power to weight and total weight bases. Oil engines would be available at 5-7 lb. per b.h.p.He further expected that the power mentioned for petrol engines would be attained without the need for excessive speeds, and he mentioned 3,200 r.p.m. as being the limit.
Explaining the differences in the compression ratios of engines for .cars and. commercial vehicles, he said that about half the cars 'in America use premium petrol of high anti-knock quality, but the average car operates 85 per cent, of the time at part throttle when the octane requirement is low. Commercial vehicles on the other hand run 85 per cent. of the time at full throttle where the octane requirement is
high. Generally speaking also, their cylinder bores are larger, which means that for a certain level of anti-knock quality, a lower compression ratio is needed. The economical limit with oil engines is a compression ratio of about 18 to I.
Life Upsetting Anvils Extended
CONSIDERABLE use is now made of electrical upsetting. This is used frequently, for example, in making engine valves. It has been found, however, that at temperatures in excess of 1,000' C., and using a fairly high pressure, the material of the anvils is apt to be overstressed. Various materials have been tried but even with tungsten steel, cracking often shortens the life of these parts. .
It was therefore decided that a coating with a material resistant to high-temperature cracking should be tried. A successful material used for coating valves is Brightray—an 80/20 nickel-chromium alloy—and a coating of this has now been tried on these special anvils. It can be applied easily by oxy-acetylene welding, after which the face is ground fiat. If the surface becomes slightly damaged in use, it may be reground and the anvil returned to service.
"Mechs" Improve Their Publications
CONGRATULATIONS to The Institution of ."^-' Mechanical Engineers for making such great improvements in their publications, particularly their journal, now named The Chartered Mechanical Engineer. That superseded was admittedly old fashioned and unattractive, whilst the summaries of papers were often so brief that they conveyed only a poor idea of the subjects with which they dealt.
The new journal is bright, well printed on good paper and much more informative. It contains a higher proportion of technical information and the summaries of papers accepted for publication will appear in the journal some four-eight weeks in advance of presentation. .
The Proceedings of the Institution and of the Automobile pivision', will be bound annually and will be available at a reasonable charge. Each paper will appear in full, with its discussions, as a separate issue which Will be supplied to members on demand.
Help for the Incapacitated
A STRONG appeal for help in endowing the -1-1, Nuffield Nursing Home is shortly to be made throughout the industry by Mr. H. G. Henly. The total amount required is £400,000. Earlier approaches to certain distributors, dealers and overseas agents, have brought promises of about £230,000, but soon every motor trader of note is to receive a personal request which will involve about 18,000 letters.
Contracts have already been signed for the purchase of a fully equipped home in Ealing, London, which is to be opened during the first half of this year.
A great service will be performed by this new establishment in attending to the requirements of those members of the industry who, unfortunately, require more personal attention than can be given in the rest home owned by the Motor and Cycle Trades Benevolent Fund. Apart from this, greater numbers will be given invaluable help.