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).
Test report on an 'IMCO' Autopulse Fuel Pump fitted to chassis 9.EX, comparing its performance to the Autovac system.
| Identifier | WestWitteringFiles\P\2July1926-September1926\ Scan155 | |
| Date | 13th September 1926 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/AJL. c.c. to EJ. Wor.{Arthur Wormald - General Works Manager} c.c. to RG.{Mr Rowledge} R.{Sir Henry Royce} c.c. to DA.{Bernard Day - Chassis Design} EY. c.c. to OY. ORIGINAL Hs{Lord Ernest Hives - Chair}/AJL1/LG13.9.26. 'IMCO' AUTOPULSE FUEL PUMP. X3800 X3579 This pump has been fitted to chassis 9.EX and has run 835 miles. It was sent to us by Springfield as an alternative to the vacuum feed. It has not been entirely satisfactory in service. On one occasion when changing down from top gear to a lower gear on a hill that necessitated full throttle, the pump failed momentarily to supply the required amount of petrol to the carburetter. This is the only actual failure during the test. It has been noticed that the carburation has been extremely erratic on this car ever since the Autopulse pump was fitted: this appears to be due to the pump not keeping as constant a petrol level in the carburetter as does the Autovac. The carburetter petrol levels comparing the Autovac and Autopulse systems under similar conditions were found to be as follows :- AUTOPULSE - stationary 1.0". Light running 1.3" to 1.6". AUTOVAC. " 1.2". " 1.7". (The figures given are the measurements from the float chamber top face to the petrol level in the jets). The Autopulse increases the level under both conditions and does not provide a constant level under light running conditions. A small delivery valve in the contd :- | ||