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).
The failure of an A.C. T type petrol pump during high-temperature testing on a Wraith car in France.
| Identifier | ExFiles\Box 108\1\ scan0116 | |
| Date | 27th August 1937 | |
| Hs{Lord Ernest Hives - Chair}, C to By, Da{Bernard Day - Chassis Design}, Mx.{John H Maddocks - Chief Proving Officer} we have received the following report from Dixon since his visit to France To. Rm.{William Robotham - Chief Engineer} CHATEAUROUX. Rm{William Robotham - Chief Engineer}/JBD{John B. Dixon - Fuel Systems}/1/JAB.27.8.37. 600a Petrol Supply on Wraith 26.G.VI. A failure of the A.C. T type pump now fitted to the above car occurred after a halt near the summit of the Col de Tourmalet, when the under bonnet temperature at the pumps rose to 68°c. No starvation was experienced during the climb in spite of the fact that the car was boiling hard, no fan being fitted. After 10 minutes we attempted to proceed. The car started without difficulty but after 20 yards, the car was brought to a complete standstill with no petrol in the carburetter. Attempts to start the car on the starter failed and we resorted to the hand priming lever on the pump to fill the carburetter without success. This occurrence drew the attention of some English tourists in a Ford V 8, who spotted the fact that the car was fitted with an A.C. pump identical to their own and on which they had experienced trouble. We explained the fact that it was purely experimental and proceeded to rapidly connect up the RR. S.U. pump in the dash. With this arrangement we made a successful get-away and completed the climb, the speed being limited to by petrol starvation to 20 MPH. in 2nd gear. A similar failure of the large type A.C. pump as fitted to the Oldsmobile occurred in the Alps, and it is this pump that was intended for the Wraith. From these experiences we have lost confidence in the mechanical pump and from experience last year in France on 22.G.V. we know the limitations of the S.U. pump mounted on the dash. We are confident that the S.U. pump in the frame will safeguard the Wraith from starvation even in extreme conditions. It has however only been possible to test this arrangement up to an air temperature of 30°c, when one unit alone was sufficient to give maximum M.P.H. The Phantom III has proved that it is possible to run with this system up to 37°c air temperature. The pump in the frame is mounted under the driver's seat and is made acessible by removing the seat and board underneath it. A full report is attached. ----------------- Rm{William Robotham - Chief Engineer}/JB D.{John DeLooze - Company Secretary} J.B.Dixon | ||