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 cooling tests, focusing on ventilated bonnets, radiator performance, and car comparisons for hot climates.
| Identifier | ExFiles\Box 29\3\ Scan202 | |
| Date | 25th June 1930 | |
| Hs{Lord Ernest Hives - Chair}/Rml/MJ25.6.30 contd. -3- We think that it is essential to fit ventilated bonnets to cars going to hot climates because the critical atmospheric temperatures at which the car will boil is certainly at least 10°C. lower when running full throttle than when touring at 60 M.P.H. as in these tests, which means that even with the cooling system in 100% condition, anything above an atmospheric temperature of 25°C. will cause trouble. This is indicated in Graph (4), though little all out work was carried out becuase the tyres would not stand up to it, the track being in poor condition. It appears to us that if we do not increase the facilities for the air to get away from under the bonnet, we cannot take advantage of the increased frontal area of the Phantom II radiator, and so counterbalance the decrease of tube length from 4.5" to 4.00" which took place when we went from Phantom I to Phantom II. 18-EX. Car. We compared this car with 19-EX. The results are given in Graph.(6). We attribute some of the increased temperature to the special pistons fitted to this car becoming tight. Variations in Radiators. We tested two radiators made of the same parts. The results shew that we can get appreciable variations in the cooling of radiators made to the same drawing, and weare investigating the reason for this discrepancy. Oil Temperature. The temperature which the oil inlet to the engine | ||