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).
Design and effectiveness of louvred bonnets compared to shutters, with a suggestion from Mr. Royce.
| Identifier | ExFiles\Box 66\3\ scan0105 | |
| Date | 23th September 1925 | |
| To Hs.{Lord Ernest Hives - Chair} from DA.{Bernard Day - Chassis Design} +8260 DA{Bernard Day - Chassis Design}12/M23.9.25. LOUVRED BONNET X.8260 X.4214 The louvres following on the lines of the Hispano which we saw on the bonnet of 7-EX, were a considerable improvement on the previous louvres. Mr. Royce would like to try some of approximately this pitch, but which are half bent inwards, and half bent outwards. It is understood however that louvres are not appreciably more effective than shutters when the latter are opened, the only advantage from a coling point of view being that they are always open. As however they accentuate noise and fumes from the engine, andhave no advantage from a cooling point of view over the shutters, it is to be recommended that they should never be used where it can possibly be avoided. MADE AT CROXLEY DA.{Bernard Day - Chassis Design} | ||