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).
Proposal and diagram for a chassis fuel feed system using an engine-driven vacuum pump.
| Identifier | ExFiles\Box 77\4\ scan0019 | |
| Date | 26th April 1917 | |
| X.3503. Extract from E1/G30119. (7) CHASSIS FUEL FEED SYSTEM Consideration of the vacuum feed system shews that there are sufficient advantages to be gained by its use to justify experimenting with it. Mr. Royce proposes to overcome the chief objection to it, namely, that of sucking from the induction pipe, by using a small engine driven pump to create the vacuum. This would make the system very reliable, and enable it to operate without doubt, for example, on French roads where there are very long stretches of full throttle heavy consumption work. The vacuum pump can be a simple one with inlet ports uncovered by the piston, and an exhaust valve in the head. The Autovac system uses a gravity operated drain valve from the suction tank to the service tank. Mr. Royce disapproved of this, and proposed to positively operate this valve from the float mechanism. He further suggests using only one air valve, which would shut off a little intermediate chamber from which the engine driven pump was sucking, as shewn in the sketch below, to create the vacuum which draws the fuel from the main tank on the car. When the float is in the up position, the pump would suck normally from the atmosphere without drawing vapour from the suction tank by this arrangement. (T) (S.D. 408. 26-4-17.) Bm(.) 2/156/13. | ||