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).
The experimental use of magnesium for crankcases and other car components.
| Identifier | ExFiles\Box 140\3\ scan0055 | |
| Date | 25th August 1936 | |
| -3- Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}3/KW.25.8.36. Our own experience of car work with magnesium has been that we have had entirely satisfactory results on gearboxes and clutch pits. We were not successful in running magnesium crankcases made from the aluminium pattern, but this was not surprising, particularly in view of the fact that even in aluminium the crankcase was right on the limit, and we have had to make considerable alterations to induce the present design to stand up to the big bore power output. The difficulty of obtaining magnesium castings for experimental work has of course been that in order to get a casting the pattern is required for some little time by the magnesium foundry. With the present state of production it is quite impossible to spare any pattern for the required period. Therefore if an experiment is to go forward in magnesium, a separate pattern must be made. We are raising the question of magnesium again because in the Ph.III we have an opportunity of saving more weight by using lighter alloy than aluminium than ever previously. In the integral cylinder block and crankcase construction we have a structure which is so inherently rigid that it seems ideal for an experiment with magnesium. The decision which would have to be taken would be to make an additional pattern for the Ph.III block and crankcase, and allot it to work on magnesium. The machining does not present any difficulty, the existing jigs and tools being suitable. Devereaux had a look at the piece and thought it could be cast. We should not recommend going ahead until Leylands have completed their present experiments. It appears to us that in the immediate future a great deal of work is going to be done on magnesium alloys, in view of the large sum of money which is going to be devoted to the purchase of metal bladed propellors, and if we go forward with this experiment we shall be in a position to take advantage of any improvements which may be made. If there is a bigger demand for the material, it is reasonable to suppose that the price will come down. It seems incredible that Leylands, who are making commercial and not luxury vehicles, and who have certainly not failed to return a profit during the last few years, shouldbe able to afford magnesium while Rolls-Royce cannot. | ||