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).
Technical memo discussing engine weight reduction strategies, including piston materials and crankcase modifications.
| Identifier | ExFiles\Box 3\3\ 03-page077 | |
| Date | 1st January 1922 guessed | |
| (3) Alexandin metal has been used experimentally with some success for the purpose of obtaining light pistons but its suitability for this purpose does not seem to have been established. With reference to the removal or reduction in thickness of metal, this method could best be pursued by a systematic examination of all parts used on the engine. An examination of the crankcase top half has been made and the following suggestion might be considered with a view to reducing its weight. It is undoubtedly most important that the engine should have a stiff crankcase to resist the bending stress set up by the couples in the first half of the engine due to pistons, con rods and cranks, balancing the couples in the rear half. The transverse webs of the engine however, contribute very little to the strength of the case in this respect, their chief duty being to act as truts and lateral stiffeners to the main shell and distance pieces between cylinders and crankshaft. They transmit the stresses to the main shell. Without incapacitating them from performing this function it may be possible to lighten the existing webs, which are at present 7/16" thick, by casting holes as shown in attached sketch, or else reducing their thickness to about 7/32". Handwritten notes in left margin: See yes Y product. I have drawing completely. I should prefer holes rather than reducing thickness. | ||