Nimonic Hot Tops and Heat Shields
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WHILST nickel 'alloys have played an VV essential part in the development of gas turbines, applications to diesel engines have been mainly restricted to precombustion .chambers, turbochargers and the facing of exhaust valves, but with the advent of , higher b.m.e,p.s it is probable that accommodation of elevated temperatures will be provided by the use of high-grade heat-resistant alloys. This is substantiated by news from Henry Wiggin • and Co. Ltd.,. Hereford, that Nimonic alloys are being used experimentally for piston hot tops and cylinderhead heat shields.
Nimonic alloys have a high strength and poor heat conductivity, both properties being of value in these. applications as a means of resisting heat and avoiding excessive loss of heat; raising • the temperature of the combustion charge ill a diesel-engine cylinder. is conducive to iirficieney so long as the charge is not overheated in the intake manifold and passages. A heat shield has been fitted lathe flat surface of a cylinder head with apertures for the valves. The shield is not welded to the head and the minimal air space between the shield and .head roc-laces heat conductivity and increases heat reflection to the 'combustion space. In addition to being resistant to heat, the piston hot top reduces heat transfer to
the body of the piston,P.A.C.B. . .
Road' ResearchDays
rIPEN days will be held this year by the Road Research Laboratory at Harmondsworth, -near, London Airport, on April 29 and 30, to show the work Of the materials and construction
the overseas group, and the bridges. section; exhibits will include research into motorway design and maintenance. Admission is by invitation, and application's should be made to the Director Of Road. Research at the 'laboratory.
Separate announcements are to be made later about the open days for the traffic and safety division at Crowthorne, Berks, on September 23 and 24, and for the Scottish . branch laboratory at Thorntonhall. near GlasgoW, on June 3 and 4.
GUY EXPANSION UV' MOTORS (EUROPE) LTD. Li have completed negotiations for the purchase of the Paget factory in Wolverhampton. This factory is adjacent to . the existing Guy factory and will be used to expand Guy's manufacturing facilities, The rked for additional premises had become necessary as 'a result of the considerable increase in the volume of business now being received by Guy for its bus and truck chassis, production of which has more than doubled in the past 12 months. says the company.