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).
Visit to Brooklands to compare the cooling performance of different fans and radiator matrix blocks on a 30.G.VII and a Buick.
| Identifier | ExFiles\Box 125\3\ scan0125 | |
| Date | 3rd July 1939 | |
| To By.{R.W. Bailey - Chief Engineer} c. Da.{Bernard Day - Chassis Design} c. Da{Bernard Day - Chassis Design}/Ev.{Ivan Evernden - coachwork} c. Da{Bernard Day - Chassis Design}/Jnr.{Charles L. Jenner} VISIT TO BROOKLANDS WITH 30.G.VII & Buick. The above cars were run at Brooklands on the 6th. 7th, and 8th. June 1939 with the object of determining their comparative cooling values, and also comparing two matrix blocks and a number of fans. Maximum speed and towing tests were carried out with most of the arrangements, and idling figures were obtained where possible. The principal results obtained were as follows :- (1) Comparison of fans. Three fans were tried, i.e. standard Wraith, standard Wraith with 5.500 blades in place of the 6.00 blade, and the Buick fan, and a datum run was carried out with no fan. From results shown on Fig.I, it will be seen that on an average the short bladed fan with an increased set on the trailing edge of the blades gave about 2½% lower critical air than the standard fan. Without the increased set, only a flat out run was carried out, and results showed a slight increase in the critical air temperature over figures obtained with the modified fan. This is rather difficult to understand, and is probably due to experimental error. The Buick fan dropped the critical air temperature by about 10%, and was inclined to be noisy, a fault also experienced on the standard Wraith fan and the short bladed fan with increased set. Short blades without the set gave quite a reasonable fan noise and were not objectionable. Comparing the best results with those obtained with no fan, we get a gain of about 25% in cooling due to the fan under full throttle conditions. (2) Comparison of Matrix Blocks. Figure II shows a comparison of the two radiator inner units, taken for test, the difference between them being | ||