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 into choked petrol jets caused by fluff, detailing jet sizes and filter gauze analysis.
| Identifier | ExFiles\Box 44\1\ Scan109 | |
| Date | 25th February 1927 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to BJ. WDF. c. to RG.{Mr Rowledge} CE. c. to DA.{Bernard Day - Chassis Design} BY.{R.W. Bailey - Chief Engineer} c. to OY. HM.{Capt. W. Hallam - Head Repairs} c. to MX.{John H Maddocks - Chief Proving Officer} EP.{G. Eric Platford - Chief Quality Engineer} PETROL FILTERS X.3701 X.3700 X.4037. Experimentally, we rarely encounter a choked jet. The contention of Sales however is that they frequently deal with cars which are not giving 100% performance due to a certain amount of fluff on the jet cone. They seem to think that this fluff may emanate from the fibrous washers supplied with many drums and cans. In view of this trouble we have been carrying out some tests on petrol filters. (a) Size of RR. jets. In order to determine the size of foreign particles which are likely to choke the RR. jets, we have calculated the minimum width of the low speed jets annular passage when set to give the correct mixture. For the 20 HP. distance 'A' is .00225", for the 40/50 .00241". Therefore any particles of over .0025" dia. are likely to cause obstruction to the petrol flow. (b) Size of RR. filter. We have examined a piece of RR. carb. petrol filter gauze under the microscope. The mesh was very even, and the size of the holes in the sample examined varied from .004" square contd :- | ||