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).
Technical report discussing engine fans and cooling systems, including comparisons with Humber's designs.
| Identifier | ExFiles\Box 126\2\ scan0121 | |
| Date | 16th June 1939 | |
| -2- Rm{William Robotham - Chief Engineer}/Ed.{J. L. Edwards}8/JH.16.6.39. Co.Ltd. and the price was estimated at 1/3. each. Apparently they give no trouble and last as long as the car. (d) No particular effort was made to streamline the waterways of the pump, and a delivery of 40 gallons per minute against the resistance of the block and radiator was obtained. 2. Fans. Humber's were very interested in the 'Hayes' fan, which appears to be simply a rather more extreme case of our five-bladed fan, two of the blades being almost on top of each other on one side, and the other three blades set on the opposite side of the fan all the angles being unequal. We left them a print of our Wraith fan, with the warning that it might require slight modifications to give the best results. The fan they have used in the past, and are still using is simply a four bladed fan with angular displacement of the blades of 72°, 108°, 72°, 108°. This gave a considerable improvement in noise value, but still gave rise to beats. The blade angle used was varied from the root to the tip of the fan starting at about 40°, and tapering off to a much lower figure. It is proposed to do some tests on our own fans with this arrangement. The power absorption of Humber fans was only in the region of 5 - 7 H.P. for a four bladed fan 17" diameter, but in connection with this it should be noted that the car in our possession boiled in 12 minutes after a high speed run. No work has been done on flexibly bladed fans of any description and we did not bring the matter up for further discussion. 3. Cooling Systems. All water pipes are of large diameter construction - about 1 3/4" with a thermostatic by pass of 15/16" diam. This arrangement giving a block pressure of about 5 - 7 lbs/in.2. under normal running conditions. The water is fed into a horizontal cooling rail with eight holes arranged to squirt on the exhaust valves and ports. | ||