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).
Letter from Wellworthy Piston Rings Ltd. discussing manufacturing tolerances and finishing processes for engine components.
| Identifier | ExFiles\Box 115\4\ scan0047 | |
| Date | 18th January 1940 | |
| 1020a WORKS TELEPHONE LYMINGTON 520 WORKS TELEGRAMS "WELLWORTHY" PRIVATE TELEPHONE LYMINGTON 232 MANAGING DIRECTOR'S OFFICE JH/MS. W.A.Robotham, Esq., Messrs. Rolls-Royce Limited, DERBY. Dear Mr.Robotham, Thank you for your letter of the 9th instant in which you ask various questions. The replies to these questions are as follows - 1. Yes. We are doing this finishing by diamond boring, but we should require the width and tolerance of the conn. rod, diameter of crankpin and its tolerance, width between crank web with its tolerance. 2. The first question really answers this, because in our opinion, particularly with AC.9. no touching of the surface after the diamond boring should be permitted, and where this has been carried out we have had extremely unsatisfactory results. Where they have been fitted without any touching up by hand, provided that it has been fitted to the right tolerance, and conn.rods to the right tolerance, we have had extremely satisfactory results. We are finishing the Leyland bearing complete and they go straight from us. After the diameter and bore have been finished to close tolerance and joint faces have been married up, the job can be put into the boxes and sent, for them to either assemble at Leylands or any of their Depots without any work whatsoever and without the necessity of keeping any two halves together. Now, one case that might be of interest to you is De Havillands. They started by hand fitting and then found it necessary, to get satisfactory results, to get four or five thou. clearances in the bearing, but when they fitted (Contd.) | ||