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).
Graph showing the ambient temperature at which a Standard PII Cabriolet will overheat under various ventilation conditions.
| Identifier | ExFiles\Box 24\5\ Scan241 | |
| Date | 2nd July 1938 guessed | |
| GRAPH II STANDARD PII CABRIOLET 19 EX. AXLE RATIO 14 x 52 WT 48 CWT EMPTY TEMP. AT WHICH CAR WILL OVER-HEAT EVENTUALLY (100°C - TOP WATER TEMP.) 10°C 20°C 30°C 40°C 50°C STANDARD NO VENTILATION 35°C REAR BONNET SHUTTERS OPEN ONLY 37°C FRONT UNDERSHIELD OFF 38°C FRONT BONNET SHUTTERS OPEN ONLY 38.5°C FRONT AND REAR BONNET SHUTTERS OPEN 41°C LOUVRED BONNET. 41.5°C LOUVRED BONNET VENTILATED FRONT UNDERSHIELD 43.5°C FOR THIS TEST CAR DRIVEN AT A STEADY 60 M.P.H. ROUND BROOKLANDS TRACK. C.O CLOSED. DURING TESTS ATS TEMP AVERAGED ABOUT 21°C. VARYING FROM 17°C TO 24°C (COMPENSATED FOR ON EACH TEST) COMPARISON OF VARIOUS ALTERATIONS TO CAR. STANDARD RAD 6 m/m 7 1/2 m/m TUBES 4.00" DEEP FRONTAL AREA. | ||