MAGNESIUM FOR CARS
THE Journal of the Magnesium Industry Council, issue no. 14/1967 was devoted to the use of magnesium in cars. The cover depicted an artist’s impression of a 64-litre Le Mans Bentley, to supplement an Editorial about Bentleys at Le Mans, in which it was mentioned that these cars used magnesium alloy sand castings for crankcase, main bulkhead centre section, cambox cover and side plates, gearbox casing and dashboard, etc. This year’s Le Mans-winning Ford had magnesium alloy castings for pedal mounting brackets; front and rear huh carriers, rack housings, etc. Reference is also made to the Tech Del Minilite magnesium wheels used on the 13.M.C. Minis, when winning this year’s Monte Carlo Rally. These wheels, the nave and rim of which were tested over some 50,000 miles, saved 5o lb. per car. Each wheel is made from magnesium C-alloy gravity die castings, heat-treated, stress relieved, and subjected to crack detection. When Simo Lampinen had a tyre deflate on a tight section he covered 8 km. on the bare rim, which would still have taken a new tyre, whereas, in the opinion of the B.M.C. set-Vice crew, a pressed-steel wheel would have disintegrated. Magnesium wheels used on Matra/B.R.M., G.P. Lotus, Rally Lotus-Cortina, Kai-mama Ghia VW and Le Mans Austin-Healey Sprite are illustrated. Other examples quoted of the use of magnesium to save Weight and improve heat dissipation are Hewland gearbox casings, varying in weight from 18 lb. to 35 lb., these having been used by Hewland since their formation in t959, normally with a black chromate treatment, and for the castings of the Indianapolis Ford d.o.h.c. racing engine, in which the
r2-1b. oil pan, Si-lb. front cover and gear cover were of magnesium, saving 80 lb. over cast-iron. The Lola Aston Martin employs magnesium for wheels, front and rear suspension components, a saving of 78 lb., and for the front timing cover, top cover, water pump housing and Sump of the engine, while its Hewland LG gearbox has the aforesaid 35-lb. casing. The kerb weight of the Lola Aston Martin is given as approx. 1,750 lb., or 700 to Boo lb. less than the weight of the Ford GT Mk. II.
It is claimed that magnesium .alloys can be machined up to ten times as fast as steel, twice as fast as aluminium, lubricants and coolants being unnecessary, that they are less prone to corrosion than cast-iron or steel (although a protective coating is desirable), and that argonare welding gives strength efficiencies of 75% plus.—W. B.