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 fuel delivery rates and flow obstructions related to banjo unions and needle valves.
| Identifier | WestWitteringFiles\T\2July1929-December1929\ Scan126 | |
| Date | 7th November 1929 | |
| -2- Hs{Lord Ernest Hives - Chair}/3m2/AD7.11.29 contd. State of Supply Delivery Pts/Hr. (5) Banjo coupled up. Delivery taken through bottom of valve seat unit (G in sketch) 59 pts/hr. (6) As (5) but delivery taken through needle valve seat (E) 78.0 pts/hr. (7) As (6) but delivery taken with needle valve in position (A) 75.0 pts/hr. We are satisfied that the engine requires about 85 pts/hr. at full throttle and assume that it only gets it because it creates a depression in the float chamber thereby tending to make the needle seat into a high speed jet. From the previous figures it is clear that the main obstructions to the flow are (a) The inlet and outlet connections of the filter. (b) The banjo union. (c) The seating of the needle. (a) We are working on the passages in the filter head and shall get something back at this point. (b) We find that banjo unions appear to be fundamentally bad for flow because even with a larger banjo and slotted transverse holes we cannot get the flow we obtain with the normal straight through union for 5/16 pipe. We are therefore reverting to this type of union. (c) We have proved that the restriction is in the dia. | ||