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).
Report comparing the cooling performance of the 10-EX model against a standard car, with conclusions on bonnet ventilation.
| Identifier | ExFiles\Box 29\3\ Scan171 | |
| Date | 12th September 1927 guessed | |
| contd :- -2- of the rear seat rises 5°C or so when the car is allowed to stand after a fast run i.e. it is the heat that rises vertically that causes unpleasantness, and when running, the draught between the shield and silencer body removes the majority of the heat. (g) 10-EX v.{VIENNA} Standard car. 10-EX is certainly no worse cooled than a standard car at max. speed. The dimensions of the radiator altered are :- Standard tube length.................... 4.75" 10-EX " " .................... 4.5" Reduction in matrix depth - 10-EX. .... 5% Increase in frontal area - " " .... 6% over 'W' series. The points in favour of 10-EX are - high compression and high axle ratio; against this car - the fact that a greater H.P. is being developed. CONCLUSIONS. (1) If the driving seats of sports bodies are low and well screened from all wind as appears inevitable, permanent bonnet ventilation will be most desirable. (2) Louvres are a more efficient means of high speed ventilation than shutters. (3) The short tube radiator should be quite satisfactory with bonnet ventilation. (4) A complete undershield is undesirable with-out some form of oil radiator. Our tests shew that even with no undershield the oil attains a temperature of 75°C with a louvred bonnet. With the standard arrangement conditions would apparently be somewhat worse. contd :- | ||