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).
New air pump for the Falcon X engine, comparing its performance and modifications.
| Identifier | ExFiles\Box 37\4\ scan 076 | |
| Date | 22th June 1917 | |
| H.R. 255a 1770 H.S.&D.{John DeLooze - Company Secretary} 442. 9-5-17. G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 1965 To By.{R.W. Bailey - Chief Engineer} from Oy. c. to Wor.{Arthur Wormald - General Works Manager} c. to EH. c. to EP.{G. Eric Platford - Chief Quality Engineer} c. to E.{Mr Elliott - Chief Engineer} c. to EFC X.3099 Oy1/B22.6.17. X.3099 - RE AIR PUMP FOR FALCON X. 2908. I enclose herewith Lec.824 You will have noticed doubtless, that through retaining the 2 magneto design on the Falcon engine our air pump does not fulfil at present the terms of the specification, which called for 600 cubic inches of air per minute at 4 lbs. pressure. The new pump satisfies these conditions. It has the same bore as the air pump on the 4-magneto Eagle, a 1.1" stroke instead of 1" on the 4-magneto Eagle, and a slightly reduced clearance volume. The result is that the delivery is .79" cubed per stroke at 4 lbs. pressure at ground level, and .7" cubed per stroke at 4 lbs. pressure, (gauge pressure) at an atmospheric pressure of 10 lbs. per square inch, corresponding to about 11,000 ft. Thus the pump will deliver 790 cubic ins. per minute at ground level on the Falcon and 700 cubic ins. per minute at 11,000 ft. on the Falcon. On the Eagle running at 1800 revs. we should deliver 710" cubed a minute at ground level and 630" cubed per minute at 11,000 ft, so that if on the new Eagle we should return to the 2-magneto design (which does not seem probable) we can put on this pump as it stands. You will notice that we have taken the relief valve off the pump and are going to put it on the petrol tank, sending it out screwed with a sparking plug thread to suit a screwed socket on the tank, which will have to be made by the aeroplane makers. On the air pumps at present, we understand that the safety valve on the cylinder has to be set up to blow off at 6 lbs. Contd. | ||