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).
Ignition failure on a trials Bentley, discussing the rocker arm bush material and pin corrosion.
| Identifier | ExFiles\Box 163\7\ img223 | |
| Date | 14th December 1933 | |
| 86120. To Sg.{Arthur F. Sidgreaves - MD} from E.{Mr Elliott - Chief Engineer} E.11/HP.14.12.33. c. Mr. Hs.{Lord Ernest Hives - Chair} by.{R.W. Bailey - Chief Engineer} Hs{Lord Ernest Hives - Chair}/Wst. [text crossed out: Dodds] re Bentley. Replying to your memo sg.{Arthur F. Sidgreaves - MD}12/E.13.12.33 with regard to the ignition failure experienced by Professor Dodds on a trials Bentley, this rocker arm is an RR. designed piece although it is bought out complete from Watfords. The material of the bush is not fibre but bakelite dilecto or, in other words, layers of cotton or linen fabric impregnated with bakelite gum and heat-treated under great pressure to produce a solid non hygroscopic material. The fibre bush as used in the old days undoubtedly swelled up and seized due to absorbing moisture, but we are certain that this trouble does not occur with bakelite. It is true that we use phosphor bronze on the RR. chassis but the bakelite is regarded as an improvement which we hope to standardize on all cars and which is used by the Delco Remy and other standard ignitions because it is more or less self-lubricating and although a spot of oil or grease is used with it it is not essential, as in the case of the bronze bush. We think the difficulty really lies with the pin on which the rocker is mounted as this pin is subjected to the corrosive effects of the nitrous oxide fumes formed in the distributor. The material we use on the RR. and have used on the Bentley hitherto is nickel steel for the pin and in the case of our RR. chassis it is our custom to protect this with a coating of lanalene and rely on a spot of oil being given at infrequent intervals afterwards during the working life of the car. Actually we have had a case of failure on an experimental Bentley with this pin rusting up, and after inserting a clean pin in the bush of the lever which you sent to us we found signs of discolouration which might very well be associated with a thin layer of rust having formed on the original pin. We have tried on the RR. cars using stainless steel [Handwritten note in left margin next to 'infrequent intervals']: but regular | ||