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).
Vehicle cooling system performance and factors affecting overheating.
| Identifier | ExFiles\Box 29\3\ Scan223 | |
| Date | 9th July 1930 | |
| HS{Lord Ernest Hives - Chair}/Rml/MJ9.7.30 contd. -6- efficient fan, a rich mixture and a ventilated bonnet the car should not over-heat at air temperatures below 35°C. when driven all out continuously in still air, and if driven at 75 M.P.H. indefinitely should not over-heat below atmospheric temperatures of 40°C. Under these circumstances we should say that the limiting factor in driving the car fast would be the tyres and not the cooling system. The effect of a following wind is very marked if the fan is not working. Even when the fan is working a following wind can easily raise the top water temperature 5°C. We think this may account for some of the figures in the daily reports such as that of 6.7.30. Max. Water temp. 100°C. Average " " 82°C. Max. air " 28°C. Average air " 25°C. We will ask G.W.Hancock to specify exactly what conditions raise the maximum water temperature 18°C. above the average while the air temperature only rises 3°C. Incidentally, one of the old standard whittle fan belts is being run on 24-EX. We are sending one of the new belts out as soon as we can obtain a fresh supply. We think it is wrong to condemn the cooling system of the car because the daily report shews 100°C. as having been reached, because it may only have been attained moment- arily without loss of water. | ||