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).
Letter replying to three queries about the effects of using thin lubricating oils in a vehicle.
| Identifier | ExFiles\Box 145\3\ scan0110 | |
| Date | 15th July 1937 | |
| Rm{William Robotham - Chief Engineer}15/R.{Sir Henry Royce} 15th July, 1937. A.{Mr Adams} Duckham, Esq., Duckham House, 16, Cannon Street, E.C.4. Dear Mr. Duckham, I apologise for the delay in answering your letter of the 6th July. Replying to your three queries:- (1) The impression is that engine noise generally does increase with thin lubricating oils. In our particular case, timing gear noise increase seems quite as noticeable as that of the valve gear. (2) There is not a bigger consumption on the one shot lubricator unless the owner uses the pump more frequently. The pump operating pedal comes up more rapidly, but we do not recommend increasing the number of strokes when a thin oil is used. (3) Naturally, when a thin oil is used, there is a greater tendency for it to pass the piston rings, and also to be lost through oil leaks. This means that there is a slightly greater tendency for oil vapour to be present in the clutch pit, unless the crankcase ventilation is modified to deal with the problem. Unless, of course, the car is on the border line for clutch slip, it is exceedingly unlikely that the difference produced by the thin oil would cause any trouble. It was unfortunate that you were unable to come to Derby, and I am looking forward to seeing you at some future date. Yours sincerely, | ||