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).
Page 2 of a letter discussing engine noise, valve bounce, and a request for a spare filter for a Bentley.
| Identifier | ExFiles\Box 108\1\ scan0420 | |
| Date | 25th February 1938 | |
| ( 2 ) 2/.25.2.38. At the time we did not take the revs. any higher, assuming that the clatter was valve bounce, and therefore, gave this as the valve bounce speed. We have now confirmed that the noise in question becomes no worse if the revs. are further increased and no bad valve bounce takes place within our normal speed range. We are sorry we have deceived ourselves and misled you. The new A.C. filter has removed the dirt from the engine oil. Will you please send us a spare filter for the Bentley. ------------ Rm{William Robotham - Chief Engineer}/IMW.{Ivan M. Waller - Head of Chateauroux} | ||