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 improvements for 45 HP and 25 HP models, including changes to copper tubes, weight reduction, and non-spilling valves.
| Identifier | ExFiles\Box 16\2\ Scan020 | |
| Date | 22th May 1931 | |
| Hs.{Lord Ernest Hives - Chair} } FROM R.{Sir Henry Royce} By } c. Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} PN.{Mr Northey} c. F.{Mr Friese} L. Da.{Bernard Day - Chassis Design} X7250 R4/M22.5.31. X.7250 X.5250 X.766 RADIATORS - 45 HP. and 25 HP. Referring to Hs{Lord Ernest Hives - Chair}/RmB/KT19.5.31, to get amove on we ought to adopt the .309 round copper tubes - with hexagon or rounded ends (dented) - at once. The reduced number down to 5540 (66%) should make a very definite move towards reducing costs, and the saving of 25% in weight (25 lbs.) we hear of with joy. The square tubes are not really needed as blocked radiators and internal resistance of radiator are not now feared, but they have proved better than I expected, and have not had the modern advantage of dents or being made in thin copper to reduce weight, to be correctly comparable. An atmospheric temperature of over 40° C. full out without boiling is very good indeed. We are hoping to see the new bonnet shutters instead of louvres as these could be a universal standard. The non-spilling valve in the radiator cap has proved a valuable improvement, well worth its cost, being quite effective against splashing losses (which may also be cornering) and also gives a higher barometer effect of say 4 to 6 ins. Hg. with its temperature equivalent - good also for Alpine passes. R.{Sir Henry Royce} | ||