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).
Carburetter performance tests at Brooklands comparing standard and S.U. carburetters with different bonnets and jet settings.
| Identifier | ExFiles\Box 102\1\ scan0028 | |
| Date | 6th August 1931 | |
| 85080. COPY. To Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} from F.Dodd. 6.8.31. X.788. X.1487. CARBURETTER TESTS AT BROOKLANDS ON 12-GIV.X.5080 Standard carburetter with louvred bonnet. Air Temp. | Water Temp. | Lap time | Lap Speed MPH. | 1/2 Lap mile Time | 1/2 Lap mile Speed. --- | --- | --- | --- | --- | --- 19º | 73.5º | 2-32.6 | 65.26 | | 19º | 74º | 2-32 | 65.52 | | 19º | 73.5º | 2-31.2 | 65.87 | 27.4 secs. | 65.69. Standard carburetter with plain bonnet. Air Temp. | Water Temp. | Lap Time | Lap speed MPH. | 1/2 Lap mile Time | 1/2 Lap mile Speed. --- | --- | --- | --- | --- | --- 19º | 82º | 2-31.4 | 65.78 | | 19º | 81.5º | 2-31.4 | 65.78 | 27.4 secs. | 65.69 S.U. Carburetter with louvred bonnet. Air Temp. | Water Temp. | Lap Time | Lap speed MPH. | 1/2 Lap mile Time | 1/2 Lap mile Speed. --- | --- | --- | --- | --- | --- 20º | 76º | 2-27 | 67.76 | | 20º | 76º | 2-26.4 | 67.57 | 26.4 secs. | 68.18 This test the carb. jet was set strong, 13º on marking Air Temp. | Water Temp. | Lap Time | Lap Speed MPH. | 1/2 Lap mile Time | 1/2 Lap mile Speed. --- | --- | --- | --- | --- | --- 20º | 76º | 2-28.8 | 66.94 | - | - This test the carb. jet was set in weak position. | ||