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's performance test, detailing delivery rates at various voltages.
| Identifier | ExFiles\Box 149\1\ scan0264 | |
| Date | 28th July 1936 | |
| (2) Hs{Lord Ernest Hives - Chair}/JBD.{John B. Dixon - Fuel Systems}14/JH. 28.7.36. Volts. Delivery. 12 225 Pints per hour. 10 212 " " " 8 194 " " " 6 172 " " " 4 103 " " " This test on a 1 in 3 1/2 gradient was made both with and without air bottles of 3 c.c capacity and no difference in the delivery could be found. The pump worked satisfactorily down to 5 volts but became intermittent at 4 volts. As the pump now stands there seems to be ample margin as regards capacity and delivery head and it should be suitable for what we require. It is possible you could reduce the loading on the pump to relieve the points. With the car standing on the level there was an ample delivery of 194 pints per hour 51" above the pump (12 volts) whereas the additional head due to a gradient of 1 in 3 1/2 would give a total pressure head of 39" leaving more than 12" head to overcome the resistance of the needle valve to the float chamber. It should be borne in mind that a gradient will have considerable effect when working on reduced voltage owing to approximately 24" additional suction head and in our test with the pump as it now stands gives 8 volts as the minimum voltage at which the pump would give an ample delivery. Yours faithfully, FOR ROLLS-ROYCE LTD. | ||