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 tests data showing water temperatures and radiator shutter positions under various conditions.
| Identifier | ExFiles\Box 103\4\ scan0169 | |
| Date | 31th March 1936 | |
| (2) 31.3.36. Radiator Tests Continued. 4. Spring was fitted in thermostat, and test continued with empty header tank at max. speed. Air 15°C. WATER IN ENGINE | WATER IN RADIATOR | DIFFERENCE | SHUTTER POSITION ----------------|-------------------|------------|----------------- 71°C. | 65°C. | 6°C. | Closed. 75 | 70 | 5 | " 82 | 80 | 2 | " 88 | 85 | 3 | " Shutters begin to open 95 | 87 | 8 | Half open. 91 | 85 | 6 | " 88 | 80 | 8 | " 88 | 80 | 8 | " 88 | 80 | 8 | " FLUCTUATING | 92/90/93 | 84 | 8 | " 89 | 81 | 8 | " Average 86°C. | 79.7°C | 6.3°C | 5. Last test was repeated with header tank nearly full. WATER IN ENGINE | WATER IN RADIATOR | DIFFERENCE | SHUTTER POSITION ----------------|-------------------|------------|----------------- 83°C | 75°C | 8°C | Closed. 85 | 80 | 5 | " 89 | 85 | 4 | " Shutters begin to open 93 | 87 | 6 | Half open 94 | 86 | 8 | " open. FLUCTUATING. | 90/93/92 | 85 | 7 | " 85 | 78 | 7 | " 85 | 76 | 9 | Half open. 86 | 80 | 6 | " FLUCTUATING. | 90/93/92 | 84 | 6 | " 90 | 84 | 6 | " 93 | 85 | 8 | " 90 | 84 | 6 | " Average 89°C | 82°C | 7°C. | | ||