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 in Bentley engines and a survey of oils currently in use.
| Identifier | ExFiles\Box 131\2\ scan0162 | |
| Date | 4th May 1938 | |
| #236 11/B Rm.{William Robotham - Chief Engineer} Rm{William Robotham - Chief Engineer}/GWH.{George W. Hancock - Head Chateauroux}8/G.4.5.38. RE: THE USE OF THIN OILS ON BENTLEY ENGINES. I have fully explained your requests and views to Mr. Pike of getting some known customers to run on a thin oil after having had a re-bore. Mr. Pike has made reservations to doing this, chiefly because of the fear of the Conduit Street officials blaming him in the event of one of the owners complaining if anything went wrong with the engine. He takes the view that he should be covered in writing, and that the agreement should have the approval of Conduit Street Official. To cover this, will you please put down in black and white, your requests, so that both myself and the Kingsbury Depot have the authority to carry them out. We have meanwhile been going over the known number of cars that are using thin oils, and the following are the results of the investigation. These have been taken from last November up to date. There are 53 cars running on Castrol CW. 147 " " Prices M 7 " " Mobiloil A 2 " " Shell Double. 1 " " Essolube R.{Sir Henry Royce} 3 " " Duckhams. These have been obtained from the files, which state what the owner has replied to the question asked, what oil is being used, and which/the engine is /oil again filled with after attention. Rm{William Robotham - Chief Engineer}/GWH.{George W. Hancock - Head Chateauroux} | ||