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).
Results of tests on different radiator tubes and louvred bonnets.
| Identifier | ExFiles\Box 24\5\ Scan364 | |
| Date | 20th October 1930 | |
| To R.{Sir Henry Royce} From Hs{Lord Ernest Hives - Chair}/Rs.{Sir Henry Royce's Secretary} c. to SE. Wor.{Arthur Wormald - General Works Manager} c. to R.{Sir Henry Royce} Da.{Bernard Day - Chassis Design} c. to RV. 8766. Hs{Lord Ernest Hives - Chair}/Rs.{Sir Henry Royce's Secretary}2/MJ.20.10.30. X. 766. X. 7250. X. 5250. RADIATOR TESTS. We have now confirmed the results obtained on the turbulent flow standard radiator tube. We have also tested out the 6 m.m. parallel square tube radiator under full throttle low speed conditions. The results shew that the square tube radiator is very effective at low speeds shewing a gain of 6-7° C. with a ventilated bonnet and slightly more with a plain bonnet. The turbulent flow tubes shew up satisfactorilly at low speeds being about 3° C. better than standard. We used a different standard radiator for these confirmatory tests, it will be noticed that it shews up rather better at high speeds than the one tested in our report Hs{Lord Ernest Hives - Chair}/Rs.{Sir Henry Royce's Secretary}1/AD.14.10.30. We also carried out tests on the horizontal louvred bonnet as shewn to R.{Sir Henry Royce} We find that at low speeds it is definitely 3° or 4° inferior to the vertical louvres, at high speeds there is little difference. The vertical louvred bonnet is surprisingly effective for full throttle hill climbing, lowering the top water temperature as much as 10° C. under certain conditions. Summarising our views so far, we believe that if | ||