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 and replacement procedures for main and big-end bearings on the 3½ Litre Bentley.
| Identifier | ExFiles\Box 115\1\ scan0171 | |
| Date | 8th December 1936 guessed | |
| -2- rods which entails removal of the head and decarbonising etc. 3½ LITRE BENTLEY Whitemetal main bearings which were standard on this car have no grooves in the intermediate main bearings. Whenever a new set of W/M.{Mr Moon / Mr Moore} main bearings are fitted, the intermediates should be grooved as is standard on the 4¼ with Hall's metal, the dimension of the groove whichnis continuous, being 2.300" dia. X .100 width. The latest modification Rm.{William Robotham - Chief Engineer}244 cannot be carried out on W/M.{Mr Moon / Mr Moore} main bearings on account of breaking into the steel shell thus weakening the W/M.{Mr Moon / Mr Moore} face. One W/M.{Mr Moon / Mr Moore} big end bearing failure, if the remaining are O.K. can be replaced by a new W/M.{Mr Moon / Mr Moore} bearing. If all the big ends are beginning to go we recommend that these be replaced by Hall's metal with RR.56. shims. In this case grooves should be machined in the inter- mediate main bearings as it is almost definite that a new set of W/M.{Mr Moon / Mr Moore} main bearings will be required in order to build the engine up as a good job. Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} | ||