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).
Investigation report on a noisy high-pressure petrol pump from chassis 3.CM.73.
| Identifier | ExFiles\Box 96\1\ scan0284 | |
| Date | 1st March 1938 | |
| To By.{R.W. Bailey - Chief Engineer} from Rm{William Robotham - Chief Engineer}/JBD.{John B. Dixon - Fuel Systems} c. MX.{John H Maddocks - Chief Proving Officer} c. BR.{T. E. Bellringer - Repair Manager} 361 Rm{William Robotham - Chief Engineer}/JBD.{John B. Dixon - Fuel Systems}8/MH.{M. Huckerby}1.3.38. HIGH PRESSURE PETROL PUMP NO.G5.1893 OFF CHASSIS 3.CM.73. Owner's complaint noisy when first started up, especially on one side. It was evident on the rig that the front unit was noisy when priming and that the armature was hitting the end of the pole piece on the over-run at the end of the stroke. This did not occur on the rear unit and when primed both units were quiet and worked satisfactorily. The setting of both sides was identical and correct. The spring on the front unit was slightly stronger and this unit consequently did more work and the diaphragm showed deeper indentations of the rollers than on the rear unit. By changing over the diaphragms the noise when priming followed the diaphragm. The only explanation is that as the front unit had been doing most work the diaphragm had become more pliable than the other and consequently the surplus energy available when there is air in the system is greater and is dissipated on the impact washer. It was only possible to get this noise on the rig when the suction union was slacked off. We consider the trouble is caused either by an air leak or else is due to the fact that while the car is standing either vapour or air dissolved in the petrol collect in the filter bowl which is the highest point in the system. This noise does not indicate that the pump is faulty or liable to fail. Rm{William Robotham - Chief Engineer}/JBD.{John B. Dixon - Fuel Systems} | ||