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).
Comparison of pump deliveries and pressures, with a table detailing standard versus stronger spring specifications.
| Identifier | ExFiles\Box 27a\2\ Scan161 | |
| Date | 11th May 1933 | |
| -3- The comparative deliveries and maximum pressures of the A.C. model "C" and the R.R. Lec.3417 pumps are shown in Graph V.{VIENNA} taken under similar conditions, (i.e. 12 ft. 1/4" diameter pipe line and straight delivery) from which it will be seen that the A.C. shows superiority in delivery, but it should be noted that the maximum pressures are also greater - the R.R. pump was tested with the standard spring - E.83800. --- When refitted to the engine, the stronger spring - the main particulars of which are shewn below - was included. Similar particulars of the standard spring E.83800 are also given for comparison. | Particulars. | Standard Spring E.83800 | | Stronger Spring | |---|---|---|---| | | Drawing | Actual | | | Free Length. | 2.050" | 2.050" | 1.850" | | Normal load at .634" length | 4.82 lb. | 4.89 lb. | 7.73 lb. | | Rating lb/in. | 3.41 | 3.46 | 6.38 | Hs{Lord Ernest Hives - Chair}/W.Bell. | ||