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).
Car overheating problems and potential solutions like bonnet ventilation for continental touring.
| Identifier | ExFiles\Box 47\3\ Scan101 | |
| Date | 9th June 1931 | |
| To PN.{Mr Northey} From Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} c. to C. H.{Arthur M. Hanbury - Head Complaints} Handwritten: X 4 11 Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}2/KT.9.6.31. GXO.69. J.Hutton. With reference to PN{Mr Northey}2/WTS.6.31. it is rather difficult to pass an opinion on the behaviour of this car until we know whether or not it had a bonnet fitted with louvres. If the bonnet of this car was fitted with louvres we should be disappointed with the results, though with atmospheric temperatures of 30°C. we know that even with bonnet ventilation, the 25 HP. has no excess of cooling under continental conditions of hill climbing and speed. If the car was fitted with the plain bonnet we should say the results obtained were exactly what we expect, and are precisely the same as those obtained by Mr. Geoffrey Smith of the Autocar, when touring on the continent a year ago. Under equal conditions of ventilation the 25 HP. is at present worse off than the P.II. also the car can be more easily overloaded and would be under continental touring conditions, this is likely to cause overheating when hill climbing. On hearing Mr. Geoffrey Smith's complaint, we tried to impress everybody at Works that it was wrong to send a 25 HP. touring in the Alps without a louvred bonnet, and indicated advantages likely to be obtained in Depot Sheet 181. This was to shew that the louvres were just as useful in hill climbing as on the level. We believe that the only reason why we have not a large number of 25 HP. complaints is that this car is not habitually used for continental touring. Since GXO.69 was produced, dented radiator tubes have come into production, and existing cars being made with this modification shew a definite improvement. For future cars we shall have a greater face area with the dropped radiator, and a greater cooling capacity with the American type of radiator tube. For cars that have been made all we can recommend is that a louvred bonnet be always fitted for cars likely to be taken on the continent. If this is not done, overheating complaints are bound to occur. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||