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 cooling efficiency and water pump delivery, comparing a new broad-bladed fan with the original narrow-bladed fan.
| Identifier | ExFiles\Box 24\4\ Scan316 | |
| Date | 25th September 1924 | |
| R.R. 493a (50n) (D.B. 175 25-9-24) J.H.D. EXPERIMENTAL REPORT. Expl. No. REF: Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}/L681.S. 25. EAC. COOLING EFFICIENCY AND WATER PUMP DELIVERY. We have carried out tests on the road to determine the value of the new fan on the car, and the prospects of the EAC. with regard to immunity from boiling trouble. To test the fans we took a narrow bladed fan of the original EAC. type and a 'V' series broad-bladed fan recommended by EFC. The two fans were driven at exactly the same speed. The results are very slightly in favour of the broad-bladed fan. The laboratory tests of these two fans showed a very much greater margin in favour of the broad-bladed fan; it would therefore appear that we are not going to obtain increased cooling efficiency in proportion to the thrust delivered by the fan on the testing rig. The fan fitted to 'V' series takes very considerably less power to drive it than the standard 40/50 6-bladed fan, we therefore expect a definite gain from increased life of belt. From the figures that we give you, it will be observed that EAC. 'V' series cars will definitely be better off as regards over-heating than the present standard 40/50 HP. COMPARISON FAN EFFICIENCY. 30 m.p.h. | 40 m.p.h. Narrow 4-bladed fan No.3-A.{Mr Adams} | 27.7°C | 28.6°C Broad bladed fan 'V' series. No.15. | 27.8°C | 29.9°C contd :- | ||