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).
Analysis of fuel pump delivery and injection quantities at various speeds, including a data table.
| Identifier | ExFiles\Box 179b\3\ img103 | |
| Date | 1st February 1933 guessed | |
| -13- In practice, the pump would rarely be required to deliver its maximum quantity and for ordinary development work on the engine the injection quantity is 0.235 ccs/cycle. All the oscilloscope measurements of pump lag and injection were taken at this injection quantity, hence it is interesting to compare the delivery curves at normal and maximum injection. This is done on Fig.8, hole No.3 being unplugged. It will be noted that the delivery curve at normal injection shows practically no falling off with increase of speed above 550 R.P.M., being practically constant at .230 ccs/cycle, rising to .235 ccs/cycle at 1000 R.P.M. Below 550 R.P.M. the injection quantity falls to .207 ccs/cycle due, presumably, to increased leakage past the plunger pump. The spill at normal injection is, of course, considerably greater than at maximum injection as the plunger is not now at the top of its stroke. A peculiarity has been noted in this connection. TABLE 4. Normal Injection. Maximum Injection. Pump Discharge Spill Discharge Disch- Spill Dis- Theoret- Speed ccs/ ccs/ and spill arge ccs/ charge ical RPM. cycle cycle ccs/cycle ccs/ cycle plus dischar. cycle spill ccs/ ccs/ cycle. cycle 1000 .235 .244 .479 .441 .045 .486 .462 900 .228 .228 .456 .450 .040 .490 .462 800 .229 .195 .424 .457 .035 .492 .462 700 .230 .185 .415 .458 .031 .489 .462 600 .230 .179 .409 .453 .035 .488 .462 500 .220 .182 .402 .451 .041 .492 .462 400 .207 .185 .392 .441 .052 .493 .462 336 .207 .185 .392 .428 .061 .489 .462 | ||