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).
Track visit with car 37-EX at Brooklands to investigate petrol supply drying out at high temperatures.
| Identifier | ExFiles\Box 155\1\ scan0245 | |
| Date | 15th July 1936 | |
| To Rm.{William Robotham - Chief Engineer} X1220 Hs{Lord Ernest Hives - Chair}/FD.{Frank Dodd - Bodies}19/KW.15.7.36. 37-EX at Brooklands 10.7.36. The object of the track visit was to investigate the question of the petrol supply drying out at high temperatures under the bonnet after the car has been standing for a minimum of 15 minutes. The overheating of the petrol pumps was first suspected and these were completely shielded with asbestos and a metal cover. It proved, however, that when the heat of the engine and chassis reached its maximum temperature after continuous running, we had other trouble to contend with. It was found after the car had stood for 15 mins. that the petrol pumps clicked for a few seconds and stopped dead. If we tried to get away quickly the engine starved at 50 M.P.H. for a matter of a quarter of a mile, afterwards the supply coming through O.K. The trouble was ultimately traced to petrol vapour and pressure in the supply pipe to the carburetter, the pump delivery not being great enough to clear the vapour past the float needle. Tests are being carried out to lighten the needle and static tests are to be made with the whole of a Ph.III petrol system heated to the hottest Continental conditions. The petrol temperature in the pipe line in the Vee was taken under running conditions and after standing 15 minutes and were 48°C. and 76°C. respectively - air temperature was 24°C. The lap speed was 88.62 M.P.H. The half mile was 90.00 M.P.H. Complete car weight - 52 cwts. 2 qrs. 14 lbs. | ||