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).
The use of thin oils on Bentley cars to reduce cylinder bore wear after a re-bore.
| Identifier | ExFiles\Box 145\3\ scan0180 | |
| Date | 6th May 1938 | |
| W/K - PK. from Rm.{William Robotham - Chief Engineer} c. Rm{William Robotham - Chief Engineer}/GWH.{George W. Hancock - Head Chateauroux} 1235 also 1113. Rm{William Robotham - Chief Engineer}10/R.6.5.38. USE OF THIN OILS ON BENTLEY CARS. This is to confirm that we have asked you to arrange for a number of cars to be run on thin oils after a re-bore, in particular, on cars whose owners have established a reputation for driving them in such a way that cylinder bore wear is excessive. The question is asked in an endeavour to ascertain whether or not thin oils are going to help us in reducing the necessity for re-boring. Obviously, the results are only useful if the owner will continue to run on thin oils. This question is being raised with Sg.{Arthur F. Sidgreaves - MD} at a Conference on Tuesday next, and unless you hear to the contrary, you may take it that he has agreed with the recommended procedure. Rm.{William Robotham - Chief Engineer} | ||