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).
Modifications to intermediate main bearings on experimental Bentley units.
| Identifier | ExFiles\Box 115\1\ scan0042 | |
| Date | 4th July 1936 | |
| X1070 To E.{Mr Elliott - Chief Engineer} c. to By.{R.W. Bailey - Chief Engineer} Hs{Lord Ernest Hives - Chair}/Swdl.{Len H. Swindell}1/JH. 4.7.36. Bentley. Several of our experimental units have been run with the intermediate main bearings grooved right round as on the other main bearings, otherwise the bearings are as standard production in Hall's metal. The main reason for this modification is that the oil feed to Nos. 2 & 5 big ends which are between intermediate main bearings is increased and invariably if we have any trouble of big end seizures it is either No. 2 or 5. For other than this reason the condition of the bearing surface is improved by reason of the following. The present standard intermediate mains are grooved round the cap half and only partially round the case half, so that any particles of foreign matter are forced to the end of the grooves which are a gradual run out to the surface and then carried round the bearing causing a grooved surface. This modification we recommend for production on the Bentley but are holding up with regard to the 25/30 unit until completion of oil consumption experiments which we are carrying out on the latter unit. The next 10,000 miles Bentley unit will have the continuous grooves on the intermediate bearings. Hs{Lord Ernest Hives - Chair}/L.H.Swindall. | ||