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).
Page two of a letter from The Light Production Co. Ltd. regarding the properties of alloys for pistons.
| Identifier | ExFiles\Box 86\2\ scan0133 | |
| Date | 6th November 1933 guessed | |
| - 2 - a higher temperature, but as you suggest, we should be inclined to assume that the additional heat would be taken more readily by the water jacket than the oil mist. Any doubts on this reasoning, however, point in favour of the Aerolite Piston. On the other hand, you will observe from the figures attached that the thermal conductivity of the alloy we use is inferior to that of the material from which your original pistons were made, and as a result, it could be expected that the piston temperature of the aerolites, as at present made, would be generally somewhat higher. As requested, on the attached sheet you will find the principal characteristics of the alloy we use and from these, you will see, as the writer informed you, that they are on the whole not quite so good as those offered by RR.53, but of course, we do not claim such characteristics for it, especially when the price factor is taken into consideration. It is the only alloy we know of, commercially competitive, yet having good characteristics at elevated temperature. The loss in tensile strength follows the same percentage as RR.53 with increase of temperature, and the comparison between the Brinell hardnesses at 300° C. given in the table is that obtained when both materials have a brinell of 140 at normal temperature. Yours faithfully, pp THE LIGHT PRODUCTION CO. LTD. A.H. Brooks GENERAL MANAGER. Enclos. | ||