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).
Pump delivery spring strength, pressure settings, and positioning to avoid vapour lock.
| Identifier | ExFiles\Box 31\5\ Scan099 | |
| Date | 29th August 1933 guessed | |
| -2- With regard to (c) we can foresee your objection, that a stronger delivery spring will be required in the pump which will mean that there will be a definite increase in pressure when the engine is idling in order to produce the necessary delivery at maximum speed. We suggest however that since with your pump we are now working at 1 lb/sq.in., and have been running at 4 lbs/sq.in., with our mechanical pump, that we shall find some intermediate setting which will give satisfaction with the pumps in the suggested position, i.e. somewhere half down on the chassis, and shall by this means be able to get a satisfactory job. We should at the same time like to have your views on the subject. We are fitting up an alternative arrangement with the pumps mounted off the frame under the bonnet, which we believe will prove very satisfactory for vapour lock except under abnormal conditions of temperature, i.e. atmospheric above 35°C. in shade. Yours faithfully, FOR ROLLS-ROYCE LIMITED. | ||