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).
Note on engine bores, pistons, cold knocking, and oil consumption.
| Identifier | ExFiles\Box 170\2\ img214 | |
| Date | 9th November 1934 guessed | |
| (about 1/3rd of Total friction) 2 as the latest Nelson Invar Strut type) We have them in both Low. Exe & Lynite without definite preferences either way. Cold knocking may be due to distorted bores and is not worrying us at all with the trans-slot piston. Our bores, after years of work, are fairly round. On a new engine with cylinders cast en-bloc we have a suspicion that the bores may be too round. Engine runs dry at low speeds to an extent where we fear the wear. We have not heard cold knocks or idle knocks hot, but this may be due to the soft rubber engine mount. Are doing our utmost to increase oil consumption at 50 m.p.h & decrease it at 80 m.p.h. All rings are individual cast and are very hard. They are sprung close to the limit of the iron and have about 9 lbs expansion. | ||