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).
Recommended mileage for engine decarbonisation and inspection of components like bearings and pistons.
| Identifier | ExFiles\Box 150\1\ scan0284 | |
| Date | 10th February 1937 | |
| 1282 W/S. {Derby Works / Sales} C. from Rm. {William Robotham - Chief Engineer} Rm {William Robotham - Chief Engineer} 3/R.10.2.37. P.III DECARBONISATION. Hs. {Lord Ernest Hives - Chair} has asked me to reply to your C6/C9.2.37. Unfortunately, all our experimental cars have been run on Ethyl petrol, and we, therefore, have had no experience as to how far a car will run on ordinary No.1 fuel before it requires decarbonising. If in service it is found necessary to do this at less than 10,000 miles, then we shall have to lower the compression ratio, unless by that time we have a sparking plug which will give satisfactory service with T.E.L. Unless the car suffers from pinking there is no reason why it should be decarbonised at less than 15,000 miles. With regard to the bottom half being removed, and big-end bearings, pistons, etc. being inspected, this should be done between 25 and 30,000 miles. Here again, this recommendation may have to be modified as a result of experience at the Depots. Rm. {William Robotham - Chief Engineer} | ||