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).
Comparison of cooling performance and silting for two different diameter radiator matrix tubes.
| Identifier | ExFiles\Box 15\1\ Scan157 | |
| Date | 4th October 1929 guessed | |
| -2- speeds to compare the original 7-6 m.m. diam. matrix tubes with the 7-5¼ m.m. tubes. The result of these tests shewed the 7-5¼ m.m. tubes to be slightly inferior to the 7-6 m.m. tubes The average of the tests gives the following figures :- 7-5¼ m.m. dia. tubes.:- temp. increase after 6 miles at 60 m.p.h. = 4°C. 7-6 m.m. dia. tubes.:- temp. increase after 6 miles at 60 m.p.h. = 2½°C. Against this must be set the fact that the 7-6 m.m. tube radiator gets silted up very much sooner than the other owing to the smaller space (only 1 m.m. as against 1¼ m.m.) between the tubes so that after considerable use the 7-5¼ m.m. matrix tubes give better cooling than the 7-6 m.m. diam. tubes. HS{Lord Ernest Hives - Chair}/AJL. | ||