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).
Carburettor starvation on the Phantom model, caused by petrol boiling in the Autovac fuel feed system.
| Identifier | ExFiles\Box 40\4\ Scan252 | |
| Date | 4th June 1927 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/AJL. c. to BJ. Wor.{Arthur Wormald - General Works Manager} c. to E.{Mr Elliott - Chief Engineer} DA.{Bernard Day - Chassis Design} c. to BYt. OY. X3579 HS{Lord Ernest Hives - Chair}/AJL1/LG14.6.27. AUTOVAC PETROL FEED - PHANTOM. X7510 We have experienced carburetter starvation on EAC.Vlll chassis (12-EX) which has been proved to be due to the petrol in the autovac boiling. The necessary conditions to produce this effect can, and have, been produced during normal running. It is necessary that the engine be run for a considerable time at an engine water temperature between 85°C and 100°C, then when any full throttle high speed work is called for, it is found that petrol starvation is prominent. Immediately the radiator shutters are opened the petrol in the autovac cools down and the trouble disappears. On EAC.Vlll chassis the defect is more pronounced than on the standard, due to the smaller capacity Autovac used and also to the fact that the autovac does not protrude through the dashboard, the whole tank being under the bonnet. We have produced the same effect on a standard chassis, but not so easily; it is necessary to indulge in a lot of full throttle work before any failure is apparent, even then, complete engine stoppage does not occur, but starvation is apparent. Results obtained by using a distance reading thermometer indicate that the maximum temperature of petrol in the autovac, obtainable under road conditions, is 66°C - petrol contd :- | ||