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).
The efficiency of various components on the vehicle's cooling system.
| Identifier | ExFiles\Box 29\3\ Scan266 | |
| Date | 21th August 1930 | |
| -3- Roughly, at speed, bonnet shutters increase the efficiency of the system 11½%, louvres a further 5½%. Fan. The fan appears to be just as important at high speeds as at low speeds. We have shown that by altering the blade curvature somewhat we can make it do more work. We are trying speeding it up to 1.3 times engine speed which will probably give a better result. Though the new fan belt will deal with the standard fan, we shall almost certainly require an improved drive if we are to ask the fan to do more. The simplest thing is to fit two sets of standard pulleys and two fan belts in parallel. Unfortunately, the starting handle bracket prevents this being done on the present car. In working on the fan we have in mind that it is the easiest feature to alter where we get a complaint from a customer who uses the car in exceptional conditions. Cut-out. This is definitely a means of keeping the car cool when driving fast. Radiator Shutters. As we have previously proved, fitting these does not impair the efficiency of the cooling system. Lamps etc. Our centre lamp and head lamps do reduce the efficiency of the system slightly at high speeds. | ||