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).
Summary of radiator test results conducted at Brooklands.
| Identifier | ExFiles\Box 155\1\ scan0232 | |
| Date | 19th May 1931 guessed | |
| RESULTS OF RADIATOR TESTS AT BROOKLANDS. Object of Test | Conditions of Test | Critical Air Temp. °C. | Temp. of air leaving radiator core. (Average air temp. for day - 21°C.) --- Mark V & Mark VI matrix comparison. | (1) Mark VI Matrix, standard fan, Flip-Flap bonnet - flipflaps open. 40 M.P.H. full throttle. | 26.5°C. | 61.0°C. | (2) Mark V Matrix, standard fan, flip-flap bonnet, flip-flaps open. 40 M.P.H. full throttle. | 20.0°C. | 52.5°C. Plain & Louvred bonnet comparisons. | (3) Standard Mark V matrix, standard fan, Louvred Bonnet - 40 M.P.H. full throttle. | 23.0°C. | 51.0°C. With (1) - Speed comparisons. | (4) Mark VI Matrix, standard fan, "Flip-Flap" bonnet - flip-flaps open. 30 M.P.H. full throttle. | 27.0°C. | 63.0°C. | (5) Mark VI Matrix, standard fan. As (4) but 50 M.P.H. full throttle. | 25.0°C. | 58.0°C. Fan Comparisons. | (6) As (1) but no fan. | 20.0°C. | 66.0°C. | (7) As (1). | 26.5°C. | 61.0°C. | (8) As (1) but .012" blade flexible fan. | 24.5°C. | 61.0°C. | (9) As (1) but .014" blade flexible fan. | 24.0°C. | 62.0°C. | ||