Petrol pump delivery tests with various modifications to float chamber and needle seats.
| Identifier | ExFiles\Box 31\5\ Scan073 | |
| Date | 15th July 1933 | |
| -2- Hs {Lord Ernest Hives - Chair} /WB. {Mr Brazier / Mr Bell} 8/KT.15.7.33. the needle seats when screwed tight home protruded slightly into the .187 port, causing further restriction. To reduce this, the .187 diam. hole was increased to .250", and the needle seat set back accordingly to take full advantage of the increased port. The tests were then repeated using the .125" diameter needle seat with six release holes - .125" diameter each. Finally the annular clearance round the needle seat was increased from .437" to .500" diameter. Delivery Pts/Hr. Reduction % Open Pipe. With Modifications 2B. Float chamber covers comp. .250" ports, .125" needle seats. 6 release ports. 130 116 10.5 3B. Needles removed. 130 124 4.6 4B. Float chamber covers only. .250" ports - no needle seats. 130 130 0% 2C. Float chamber covers comp. as in 2B. Needle seat clearance increased to .500" diameter. 130 118 9% By substituting a short suction pipe for the full suction system, the delivery was increased to 150 pts/hr. and the tests repeated. 2D. Float chamber covers comp. .250" ports, .125" needle seats. 6 release ports. 150 126 16 3D. Needles removed. 150 138 8 4D. Float chamber covers only. .250" ports - no needle seats etc. 150 145 3.3 The actual effect of each modification taken from one stage to the next, was very small, and considering the vagaries of this type of petrol pump the results proved to be fairly consistent. | ||
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).