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).
Summary of the disadvantages of using radiator shutters, arguing for an alternative design.
| Identifier | ExFiles\Box 39\4\ Scan342 | |
| Date | 29th December 1933 | |
| -2- Ha/Ru.13/KW29.12.33. Summarising the position, therefore, the only real justification we can see for radiator shutters at present on any car is appearance. Against this there are the following disadvantages :- (1) Cost. (2) Weight. (3) Shutters are notoriously bad for rattles when the engine is idling and when running over bad surfaces. (4) Absence of exact temperature control. (5) Amplification of fan noise. Where the shutters are close to the radiator, as on the Rolls-Royce cars, a definite roar comes from the fan at various positions of opening. This can easily be demonstrated by running up the 20/25 and the Bentley on second speed respectively. The Bentley is better. (6) Longer time to attain running temperature. In support of these remarks it should be observed that in America radiator shutters are now obsolete, and in this country even Morris has now discarded them. We think that the matter is worth serious consideration in the design of the SpectreCodename for Phantom III, as it would be unfortunate to perpetuate shutters without an effort to find an alternative. Ha/Ru. | ||