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).
Performance comparison graph for Bentley oil pumps, plotting delivery rate against pump speed.
| Identifier | ExFiles\Box 149\2\ scan0094 | |
| Date | 18th January 1935 | |
| L.E.C. 4288 BENTLEY OIL PUMPS 18-1-35 INCREASED CAPACITY HELICAL GEARS E.B. 2133/4 TESTED WITH MOBILIOL "D" AT 75°C AGAINST 25 lbs/D" DELIVERY PRESSURE WITH THE RELIEF VALVE BLOCKED UP PUMP SPEED = 1/2 ENGINE SPEED DELIVERY PTS/HR PUMP SPEED R.P.M. PUMP H1 INITIAL RELIEF PRESSURE = 17 lbs/D" PUMP H2 INITIAL RELIEF PRESSURE = 17 lbs/D" PUMP H3 INITIAL RELIEF PRESSURE = 18 lbs/D" PUMP H4 INITIAL RELIEF PRESSURE = 17 lbs/D" STD PUMP E53658 COMPARED WITH H4 PUMP (INCREASE OF 36%) H1 H2 H3 H4 WJB | ||