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).
Alterations to the big end bearings for the Wraith and 4 1/4 Litre Bentley models.
| Identifier | ExFiles\Box 115\3\ scan0002 | |
| Date | 3rd July 1937 | |
| To By.{R.W. Bailey - Chief Engineer} from Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} c. c. to E.{Mr Elliott - Chief Engineer} 1020 WRAITH AND 4 1/4 BENTLEY BIG END BEARINGS. WRAITH III. Further to our memo Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell}1/JH.30.6.37 with regard to incorporating 2 - .125" dia holes in each crankpin in place of the single .2187 dia. hole, this should also include the following alteration to the big end bearing as shewn on Ex.28171. Single central hole feed to line up with the hole through the connecting rod in place of the present 2 holes, which necessitates the milling of a groove in the connecting rod, in order that these 2 holes connect up with the hole through the rod. By incorporating the single hole in the bush the groove in the connecting rod can therefore be deleted. The particular type of big end bush we are endeavouring to make a success on Wraith is die cast in A.C.O. material Ex.28171. 4 1/4 LITRE BENTLEY. In conjunction with the standardisation sheet which has been issued for the 2 - .125" dia. holes in the crankpin, will you please incorporate the single hole feed in the big end bush and delete the grooving in the connecting rod. A Standardisation Sheet will be issued to cover this. Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} | ||