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).
Comparing different engine fans for the 3 1/2 Litre Bentley to address overheating when idling.
| Identifier | ExFiles\Box 135\1\ scan0031 | |
| Date | 14th September 1935 | |
| X1509. To: C. From: Hs{Lord Ernest Hives - Chair}/Lid.{A. J. Lidsey} C. For. E.{Mr Elliott - Chief Engineer} C. Dg. Ey. Hs{Lord Ernest Hives - Chair}/Lid.{A. J. Lidsey}7/KT.14.9.35. X224 3 1/2 LITRE BENTLEY - FAN. The Bentley car, when fitted with the Peregrine fan boils quickly when the engine is idling, i.e. as when in a traffic block. The fan is so small that very little air flow through the radiator is produced. We have carried out a series of tests using the Peregrine fan, the Standard 20/25 HP. fan, and a fan as used on the Chrysler car. The Chrysler car fan is a four bladed fan with the blades arranged asymmetrically; the object of this arrangement is to reduce fan noise. Water Temperature Rise Tests - Engine Idling. Tests carried out show that the 20/25 HP. fan is slightly superior to the Chrysler fan at slow engine speeds. The Chrysler fan, however, is far superior to the Peregrine, and no boiling takes place when idling. Power loss. The 20/25 HP. fan absorbs a large amount of power at high speeds (6 BHP. at 4250 engine R.P.M.); the Chrysler requires less than half this power to drive it at the same speed, and for this reason alone it is preferable to the 20/25 HP. fan. Noise. The Chrysler fan is reasonably quiet when placed quite near the radiator matrix. The 20/25 HP. fan is notoriously noisy if it is placed at all close to the radiator matrix. We recommend that we use the Chrysler fan on the Bentley car, adopting it as soon as possible. We presume the fan is patented and it will probably be necessary to pay a royalty on it. We are making enquiries with regard to this point. The Chrysler fan should be arranged so the the nearest point of the leading edge of the blade is 1/2" from the radiator matrix. Hs{Lord Ernest Hives - Chair}/Lid.{A. J. Lidsey} | ||