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).
Engine overheating, analysing the factors involved and referencing the 40/50 'Silver Ghost'.
| Identifier | ExFiles\Box 24\5\ Scan054 | |
| Date | 14th May 1925 | |
| R.R. 493A (50m) (D.B. 173 25-9-24) J.H.D. EXPERIMENTAL REPORT. Expl. No. REF Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}/LG14.5.25. OVERHEATING. During the past eighteen months the Expl: Dept: have done a large amount of work in connection with this problem. We feel that a brief review of the results obtained and the consequent conclusions drawn might do something to prevent misunderstanding, when considering the complaints of customers. The whole cooling problem can be divided into two parts :- (a) The number of heat units which the engine imparts to the cooling water. (b) The number of heat units which the air extracts from the radiator. When these two items balance, the cooling water attains a fixed temperature and the car can be driven without boiling. The first factor (a) is fixed by the design of engine and its dimensions. A side valve engine is almost invariably worse than an overhead valve. A large engine naturally heats more water than a small engine. A low compression engine heats more water than a high compression engine. These are known facts and have been confirmed by our tests. Now it will be observed that the 40/50 'Silver Ghost" is badly off in every respect mentioned. It is a very large engine, has side valves, and to obtain the silky running associated with RR. cars, is low compression. contd :- | ||