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).
Leaks in a modified Bijur pump and proposing a comparative test method.
| Identifier | ExFiles\Box 27\1\ Scan265 | |
| Date | 19th July 1929 | |
| X3806 TO MX.{John H Maddocks - Chief Proving Officer} from Hs{Lord Ernest Hives - Chair}/Gy. C. to By) Hs{Lord Ernest Hives - Chair}/Gyl/MJ.19.7.29. BIJUR PUMP LEAKS. A modified pump has been shown to leak under specific conditions when systematically over-filled. We had hoped that the addition of an adaptor, and a leather washer between the filter top and cover facing would prove an absolute panacea; but this is not the case, as by waiting a sufficiently long time, it is possible for the trapped air to escape through the spigot fit of the leather washer on the plunger, thereby allowing further oil to be added. On the other hand, there is evidant proof that filled up normally to the height at which the adaptor traps air, pumps will not leak when correctly constructed. We should say that this condition should be the criterion by which a pump's performance should be judged on the road, and condemned or passed on road test. As regards a static test for pump leaks, we are hardly in a position to guarantee a means for determining the difference between a satisfactory and unsatisfactory pump, because we have not yet had the opportunity of statically testing the latter. However, we can suggest the following method as being a good comparative test of Bijur pumps, and one likely to reveal errors of assembly or manufacture. Fill the Bijur tank until the adaptor just traps | ||