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).
Failures and performance of petrol pumps during endurance and alpine trials.
| Identifier | ExFiles\Box 17\5\ Scan171 | |
| Date | 24th June 1932 | |
| To R.{Sir Henry Royce} From Ha/Rn.{Mr Robinson} c.c. Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} c.c. H.{Arthur M. Hanbury - Head Complaints} Hy.{Tom Haldenby - Plant Engineer} c.c. Ds. Hdy.{William Hardy} HH/Rn.{Mr Robinson}T/KT. 24.6.32. X7460 82677 X7460 PETROL PUMPS. The present position of petrol pumps is as follows. The pump run on the last 10,000 miles test failed on the Galibier twice. An A.C. pump was taken over the same road a year ago without trouble. Some of our troubles may be due to the plate filter on the suction side, we know that A.C. do not use this, and at least one of the stoppages during the run at Chateauroux was traced to this filter becoming restricted. The gradient, low barometer, and low engine speed, all make the conditions for the pump most arduous on this climb. Repeated failures of the petrol systems of various cars were reported in the recent alpine trial, which shews that this must be regarded as a general weakness at present. Our own opinion is that the size of petrol pump standardised by A.C.'s and adopted initially by ourselves is too small for pumping at very low speeds, and particularly so for a big car with a high geared engine that turns over slowly and has a big lift on a gradient due to the big wheelbase. We put these objections to A.C.'s and they agreed with them, and obtained from the States a larger size of pump that is used over there for commercial work. This they are proposing to produce in England. We have tested the pump and attach the results. It will be seen that it does everything that we require, in particular reducing the time taken to draw from a dry line, at 40 engine r.p.m., from 1 min 20 secs, to 28 secs. This was the only objection we previously had to the A.C. pump. At the conclusion of the 10,000 miles test attention was drawn by G.W.H. to the noise produced by the R.R. petrol pump on 25-EX. This sounds like a bad tappet. It occurs when the engine is running light, the float chamber is full, and the pump is more or less idling. It is due to the push rod making the full stroke when the fabric is not doing so. | ||