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).
Report discussing cylinder liner dimensions, piston bore observations, and comparative wear figures for Bentley engines.
| Identifier | ExFiles\Box 132\5\ scan0008 | |
| Date | 11th October 1938 | |
| -2- Rm{William Robotham - Chief Engineer}/CTS.{C. Trot Salt - Carburation}9/JH.11.10.38. The liner is about 2" deep, by .062 thick. Our cylinder wall section is about .160 so it is quite practicle to consider carrying out a test. It is suggested that we fit a standard cylinder block with the best grade liner in three bores. The British Piston Ring Co. are therefore to offer their suggestions for the machining and fitting of our particular Block, but before supplying any inserts, they will give a quotation for a trial supply. It is interesting to note, that their representative made the following observations when inspecting the layout of our piston & bore. (a) That the cylinder wall section was unusually thin. (b) That the piston came out of the bore rather a lot at the bottom of its stroke. As a result of this, we are getting O.H. to supply comparative wear figures between 3½ and 4 litre Bentley, not only to show how maximum wear figures compare, but to determine whether the point of maximum wear is at the same position in the bore. Also it will be remembered that the cylinder barrels were shortened by about half an inch. The question whether this modification was good policy can be verified. Finally Mr. McCarthy stated that their experience tends to show, that normal driving produces the usual wear associated with this maximum figure at the top of the bore. The delivery van type of driving where the engine rarely gets properly warmed up, produces a max. wear figure at the point of max. piston speed, due to corrosion. Rm{William Robotham - Chief Engineer}/CTS.{C. Trot Salt - Carburation} | ||