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).
Analysis of obstructions in the petrol supply line to the carburettor and their effect on delivery flow rates.
| Identifier | ExFiles\Box 13\3\ 03-page133 | |
| Date | 7th November 1929 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson} c. SG.{Arthur F. Sidgreaves - MD} c. WOT. E.{Mr Elliott - Chief Engineer} c. DA.{Bernard Day - Chassis Design} EY. X. 7080 Hs{Lord Ernest Hives - Chair}/Ha2/AD7.11.29. PETROL SUPPLY TO CARBURETTOR. x7080 x7770 We have only just sufficient petrol supply in the float chamber to keep the car running all out. The fault in most cases is not in the Autovac being unable to draw sufficient petrol from the rear tank, though we have had experience of defective autovacs. It is that the gravity head of petrol from the Autovac to the float chamber is insufficient to supply the required quantity of petrol through the intervening obstructions, i.e. pipe, filter, needle valve. We have analysed the obstructions which bring us down from a free flow with a plain open ended 5/16" pipe of 131 pts/hr. to a delivery through the needle valve into the float chamber of only 73 pts/hr. Building up from the plain pipe we get the following deliveries. State of Supply Delivery Pts/Hr. (1) Plain 5/16" pipe from autovac to float chamber level. 131 pts/hr. (2) Empty filter head coupled up in system. 110 pts/hr. (3) Filtering element inserted in filter head. 104.2 pts/hr. (4) Banjo head fixed to end of pipe (delivery c) 97.5 pts/hr. | ||