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).
Response to a suggested method for preventing piston knock, explaining the function of the split aluminium piston.
| Identifier | ExFiles\Box 48\1\ Scan153 | |
| Date | 3rd January 1922 | |
| X4190 Expl: Dept: Hel/LG3.1.22. E.{Mr Elliott - Chief Engineer} Richards, Test Dept. 9111. SUGGESTED METHOD FOR PREVENTING PISTON KNOCKS ON R-R 40/50 HP. CAR ENGINE. With reference to the attached suggestion, we are afraid that the scheme would not be found suitable in practice. The sole object of the present split aluminium piston used on the R-R engines, is to provide a piston which will collapse instead of seize. This is necessary owing to the aluminium piston expanding considerably more than the cast iron piston when at normal working temperatures. Any scheme which prevents the piston closing in as the expansion takes place owing to temperature, defeats the whole object. We are returning herewith sketch and communication. Hs.{Lord Ernest Hives - Chair} | ||