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).
The decision to increase valve stem diameter on large bore engines for 25-29 HP and 4 litre Bentley models.
| Identifier | ExFiles\Box 106\5\ scan0148 | |
| Date | 27th September 1935 | |
| R GRY{Shadwell Grylls} X557 To DY.{F R Danby} from E/JNR.{Charles L. Jenner} c. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} E/JNR.{Charles L. Jenner}1/HP.27.9.35. 25-29 HP. and 4 litre Bentley. Owing to the failure of an exhaust valve stem in France, it has been decided to increase the diameter on the large bore engines. The inlet valve stem will be increased as well, for the sake of interchangeability of parts. We send you herewith LeC.4720 shewing the alteration as applied to the 25-29 HP. LeC.4720 herewith. E/JNR.{Charles L. Jenner} | ||