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).
Comparative test report on three types of radiators for a 20/25HP car at Brooklands.
| Identifier | ExFiles\Box 149a\2\ scan0029 | |
| Date | 2nd July 1932 | |
| R.{Sir Henry Royce} From Hs{Lord Ernest Hives - Chair}/Ltd. c. to SS.{S. Smith} c. to Wor.{Arthur Wormald - General Works Manager} c. to L. c. to Dk. c. to AY. Hs{Lord Ernest Hives - Chair}/Ltd.3/MA.2.7.32. 20/25HP RADIATOR TESTS (BROOKLANDS). We have carried out a series of comparative tests on three types of radiators on a 20/25HP car (19.G.IV.) on Brooklands track. The types of matrix tested are as follows :- (1) Standard R.R. copper hexagon tube. (2) Marston Mark II (copper strip type). (3) Harrison U.S.A. (copper strip type.) The Harrison matrix is the latest product from America and was obtained for us by Marstons. All the three radiators were fitted with matrices of rectangular form approximately 21.5"x 11" i.e. considerably smaller in area than our radiator shell will accommodate. This was done to enable us to obtain quickly the sample Harrison matrix from America. Tests were carried out under various conditions and the results obtained are given herewith. In accordance with our usual practice all water temperatures given in these results are the actual registered temperature less the air temperature recorded during each test. (1) Maximum speed full throttle - & bonnet shutters open. Type of Radiator. Max: Maintained Water Temperature 0C. Top. Bottom. Mean. R.R. Hexagon 54.3 48.3 51.3 Marston Mark III 47 41.5 44.25 Harrison 32.25 26.75 29.5 The average lap speed during the tests was 74 M.P.H. | ||