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).
Radiator, fan, and bonnet cooling tests conducted at Brooklands.
| Identifier | ExFiles\Box 155\1\ scan0229 | |
| Date | 10th June 1936 | |
| Hs{Lord Ernest Hives - Chair}/Std.13/KW.10.6.36. Report on Radiator Tests at Brooklands - May 25th & 26th. 33-EX car was taken to Brooklands on the above dates in order to estimate the effectiveness of the cooling on Ph.III and also to compare Mark V and Mark VI radiator matrices and two flexibly bladed fans. Tests. These were carried out in our usual manner, and all comparisons were made at a speed of 40 M.P.H. full throttle. This speed was selected after a preliminary test had been carried out at 30 M.P.H., 40 M.P.H. and 50 M.P.H. The cooling was best at 30 M.P.H. and worst at 50 M.P.H., but as neither of these seemed a very practical road condition for a Ph.III car, 40 M.P.H. was selected as representing a fast full throttle climb of a mountain pass. It was also intended to run a full speed full throttle test, but this proved impossible owing to petrol starvation. Further, the lamp-post float chamber vent scheme as on 20/25 was tested on this car. Results. These are shown in summarised form on the attached sheet - the difference between the two flexible bladed fans is so small as to be within the limits of experimental error. Conclusions. (1) The Mark VI matrix appears to give definitely better cooling than the Mark V.{VIENNA} A small amount of error may be present owing to the fact that the water temperatures were so near to the boiling point, resulting in some unsteadiness in water flow. (2) The flexible bladed fans tested, although very quiet - in fact inaudible at all speeds - were not as good as the standard fan for cooling. (3) The louvred bonnet gives improved cooling over the "flip-flap" bonnet. This difference would probably be increased under maximum speed conditions. | ||