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).
Controversy over radiator thickness, bonnet length, and the optimal diameter of radiator tubes.
| Identifier | ExFiles\Box 15\1\ Scan013 | |
| Date | 13th January 1927 | |
| X7250 To Hs.{Lord Ernest Hives - Chair} from DA.{Bernard Day - Chassis Design} DAL/M13.1.27. 40/50 HP. BONNET & RADIATOR ETC. X.8260 X.7260 X.8250 X.7250 With reference to the controversy which is now going on regarding the thickness of radiator, length of bonnet etc., we remember that some considerable time ago you made some tests to determine the best dia. of radiator tube, trying as I believe 7. 8. 9 and 10 m/m dia., and as a result decided on 8. as being the best. To the best of our information these were all of the stdlength - 4.750. Is it not possible that if the length were reduced from 4.750 to say 4.5, it would be desirable to reduce the dia. of say 7 mm. ? If the skin resistance of the inside of the tube is taken as a criterion of the quantity of air that can be passed through the two lengths want to be 4.75 and 4.15, and it seems almost certain that there will be a best dia. for any particular length. We do not think there is any reason why the smaller tubes should not be used, if they are found to be an advantage, and we wonder whether you have any information on this point which you could send us. It will also be remembered that the taper sided EAC.1. radiator had tubes which were 4.4" long. We wonder whether any detriment due to this has been noticed on that car. DA.{Bernard Day - Chassis Design} | ||