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).
The High Pressure Petrol Pump from the 34-EX (Nairobi car) after a 13,000-mile run.
| Identifier | ExFiles\Box 114\4\ scan0123 | |
| Date | 31th May 1937 | |
| 98 To E.{Mr Elliott - Chief Engineer} c. to By.{R.W. Bailey - Chief Engineer} 1011 Rm{William Robotham - Chief Engineer}/JBD.{John B. Dixon - Fuel Systems}3/JH.31.5.37. Report on the High Pressure Petrol Pump from 34-EX (Nairobi car). This pump has run during the whole run of 13,000 miles, both diaphragms were changed after 10,000 as they were slightly porous. When tested here on its return both diaphragms were very slightly porous but not seriously so. The pole pieces in each unit were .0035" out of centre. In one case this had caused local wear on 3 of the brass locating pieces measurement across the flats formed being .429" .425" and .424" the original dimension being .429" - .430" and the armatures were on the point of fouling the side. These armatures were made .005" smaller in diameter than the original to give a longer life before this trouble should develop. In the other unit the wear on the distance pieces were only slight the worst being .427" .4275" .428 and was not so localised but spread round the circumference as the distance pieces had been rotating about their centres and also round the diaphragm. The contact points were black owing to the porous diaphragms but were not worn or bent and the toggle mechanism had not developed slack. In view of this wear on the locating pieces I do not feel justified in rushing this pump into production unless forced to do so by vapour troubles. It requires more development to obtain less serious wear on the locating pieces. This could be obtained by either. (1) A really hard and more durable locating piece of which the difficulty will be machining and the fact that it has to be of a non magnetic material. (2) Really accurate centralization of the pole piece in the magnet pot by machining after assembly. (3) Freedom for rotation of the locating pieces. (4) A non porous diaphragm. This being essential in all pumps and we hope to obtain it with either oil silk or Neoprene. I am taking up these possibilities immediately with the S.U.Co Rm{William Robotham - Chief Engineer}/J.R.Dixon. | ||