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 the 'IMCO' Autopulse fuel pump's performance on chassis 9-EX.
| Identifier | ExFiles\Box 41\1\ Scan021 | |
| Date | 13th September 1926 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/AJL. c. to BJ. Wor.{Arthur Wormald - General Works Manager} c. to RG.{Mr Rowledge} E.{Mr Elliott - Chief Engineer} c. to DA.{Bernard Day - Chassis Design} BY.{R.W. Bailey - Chief Engineer} c. to OY. T3800 Hs{Lord Ernest Hives - Chair}/AJL1/LG13.9.26. 'IMCO' AUTOPULSE FUEL PUMP. V3579 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 even 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 Autopulse and the Autovac 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 :- | ||