From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Feasibility and cost of die-casting large aluminium parts.
| Identifier | ExFiles\Box 140\3\ scan0083 | |
| Date | 2nd November 1936 | |
| Y 1201 To Hs.{Lord Ernest Hives - Chair} From Em. c. to Sg.{Arthur F. Sidgreaves - MD} c. to Sft.{Mr Swift} c. to RHO. c. to E.{Mr Elliott - Chief Engineer} c. to Ry. Em.21/MJ.2.11.36. DIE CASTING OF LARGE ALUMINIUM PARTS. The cost of Aluminium as has been pointed out, is quite a material consideration. We think that everyone is agreed, however, that on a car of R.R. quality the use of the lightest available alloys must be indulged in wherever desirable. Aluminium has the advantage that it is easily die-cast and we were surprised to find when visiting Leylands recently that they were producing their gearboxes, which are very large compared to our own, by means of dies. We recently asked them four questions in connection with die casting i.e., - (1) On their gearbox the percentage saving in weight of metal used for casting, over a sand casting. (2) Percentage saving in hours machining. (3) Whether a satisfactory casting could be made of .175 general section. (4) Whether there is any limit to the size at which die castings would cease to be cheaper than sand. Would there be any difficulties in die casting a six cylinder one piece cylinder block and crankcase. - attached is a copy of their reply. We omitted to ask Leylands the cost of the dies and the reduction in Foundry Costs which might be expected therefrom but we are now endeavouring to obtain this information. We got a figure of £250 for a gearbox die about the Wraith size from Birmals, Benaid Works, Smethwick, Birmingham which we agree seems ridiculously low. They looked at the J.lll crankcase drawing and said it could be die cast but sand cores would be necessary unless the design was modified. We understand that the Austin Seven crankcase is now being die-cast in Aluminium and are trying to get a specimen. | ||