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).
Modification of a vacuum gear change cylinder for the 35.EX model to reduce noisy operation.
| Identifier | ExFiles\Box 94\2\ scan0326 | |
| Date | 4th January 1939 | |
| 328 To HPS.{Horace Percy Smith - Experimental Factory Mgr} from Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer} c. Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls} Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer}4/MH.{M. Huckerby}4.1.39. VACUUM GEAR CHANGE - 35.EX. The vacuum gear change with which we are experimenting on 35.EX has a cylinder approx. 4½" bore. This we believe is larger than necessary and the momentary very large efforts which it exerts may be responsible for the noisy operation. We wish to try reducing the bore of the cylinder to 3¾". When we have completed some tests which we are now doing we will hand the cylinder to you. Will you please fit a liner to the cylinder and make a new piston. We are not familiar with the inner details of the cylinder but anticipate that something in the nature of the attached sketch would be suitable. We have asked Roy.{Sir Henry Royce} to obtain two cup leathers to suit a 3¾" cylinder as soon as possible. If any questions arise during the writer's absence will you please refer them to Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls} Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer} | ||