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).
Tests conducted on a Phantom II to determine if a louvered bonnet improves cooling and reduces overheating during hill climbs.
| Identifier | ExFiles\Box 102\6\ scan0094 | |
| Date | 8th October 1930 | |
| Hd.{Mr Hayward/Mr Huddy} From Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} For Depot Sheet. X5260. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}6/MJ. 8.10.30. X.766. X.5'260. We understand that there have been one or two complaints on 20 Hp. cars of overheating when hill climbing. In order to determine whether the louvred bonnet did make an appreciable improvement to the cooling of the car at full throttle low speeds, we carried out some tests on the Phantom ll. The results shew that when climbing full throttle in top gear at 30 M.P.H. the ventilated bonnet will drop the car temperature by about 4° C. whilst at 45 M.P.H. full throttle it will drop the top water temperature by no less than 6 to 8° C. Obviously, if the hill was climbed at 30 M.P.H. in a lower gear the effect of the louvred bonnet would be greater because the fan would be circulating more air. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||