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).
Decisions on manufacturing limits for the 20/25 carburetter.
| Identifier | ExFiles\Box 102\1\ scan0359 | |
| Date | 8th July 1935 | |
| To HY{Tom Haldenby - Plant Engineer}: Copy to Mr. OFV Ha/Rm.{William Robotham - Chief Engineer} Handwritten notes: X50 / E/PSN.1/MN.8.7.35. H.{Arthur M. Hanbury - Head Complaints} Wyman } Any comment? Release - ? O.K GAD T. Salt } O.K. BUS 20/25 CARBURETTER. ------------------- At a meeting held on Friday, 28th.June, to discuss the question of manufacturing limits on the above carburetter, the following decisions were arrived at:- 1. The S.U.Co. were to be instructed that the length of the plain parallel portion of the carburetter needle, which they supply for the above carburetter, should be held to a fine limit for length, and also that a small flat should be provided on the pointed end of the needle to enable the over-all length of the needle also to be held to a fine limit. The object of this was to enable a final check of the needle position in the piston to be made by gauging the height of the needle from the face of the piston. We send you herewith LeC 4536 showing these points, and the contour of the taper portion is also specified. We should be pleased if these could be checked up with the S.U.Co. so that we shall have a record of the needle that we are using. 2. The depth of the flat bottomed hole in the central guide which receives the needle was to be finished and gauged from the face of the piston with the central guide in place. 3. The outer brass housing bush and the main jet sleeve with the jet bush pressed in are to be finished so that the face of the jet bush is level with the end of the outer bush when the pieces are assembled. This can be done either by machining the outer bush down to the level of the face of the jet bush after assembly, or by holding the lengths of the pieces to the necessary fine limits. 4. The depth of the counter bore in the jet bush itself was to be held to a fine limit and finished with a flat bottomed drill. Since the meeting, however, we have gone into this question again and are testing out a modification which deletes this counter bore, as instructed experimentally in our memo. E/PSN.2/MN.3.7.35. Although we anticipate being able to get away without the counter bore, until such time as its deletion has been tested out, its depth must be held to a fine limit. | ||