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).
Test report on petrol pump modifications and their effect on delivery rates.
| Identifier | ExFiles\Box 27a\2\ Scan204 | |
| 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 With % Pipe. Modifications 2B. Float chamber covers comp. .250" ports, .125" needle 130 116 10.5 seats, 6 release ports. 3B. Needles removed. 130 124 4.6 4B. Float chamber covers only. .250" ports - no needle 130 130 0% seats. 2C. Float chamber covers comp. as in 2B. Needle seat 130 118 9% clearance increased to .500" diameter. 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 150 126 16 seats, 6 release ports. 3D. Needles removed. 150 138 8 4D. Float chamber covers only. .250" ports - no needle 150 145 3.3 seats etc. 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. | ||