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 discussing engine pinking issues and suggesting modifications for a Bentley.
| Identifier | ExFiles\Box 126\3\ scan0132 | |
| Date | 29th April 1941 guessed | |
| The following text is from the letterhead, which is mirrored in the image: NASH & THOMPSON LIMITED ENGINEERS DIRECTORS: A.{Mr Adams} FRAZER-NASH, M.I.A.E., A.M.I.Mech.E. E.{Mr Elliott - Chief Engineer} GRATTAN THOMPSON, C.B. CONTRACTORS TO H.M. GOVERNMENT OAKCROFT ROAD, TOLWORTH, SURREY Main Body Text: 2. By ear, it is difficult to tell whether the pinking is on all cylinders or only one or two. If the latter were the case, it might be due to one of several causes on first principles:- (1) The local incandescent point referred to above, (2) The ignition not synchronised on all cylinders so that one or more are in advance of the others. (3) The compression volume more in some than in others. In view, however, of the source of manufacture of the car and ignition system, I think we can rule out (2) and (3). I had a similar trouble to this on my earlier 4¼ Bentley, chassis no. B.-102-GA, in 1936. I tried a new set of plugs without result, and finally sent the car to Neasden, where at my request they fitted the smaller carburettors and induction pipe, as fitted on the 3½ litre. They also made a detail modification to the engine. After this the car was quite satisfactory. I apologise for sending such a long rigmarole on the subject, but the car is such a pleasant one to handle and runs so sweetly, it seems a pity to lose the extra enjoyment which could be gained by avoiding this one little irritating point. There is one other feature which would be an improvement, but I am quite aware that nothing can be done about it in war time. This is for synchro-mesh to be on second speed, either in place of the one on the overdrive, or in addition thereto. There is no difficulty about changing once everything is warmed up, but until | ||