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).
Proposing an experiment to address issues with connecting rod little end bushes.
| Identifier | ExFiles\Box 132\2\ scan0238 | |
| Date | 4th January 1938 | |
| 1119 To HPS.{Horace Percy Smith - Experimental Factory Mgr} from Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell}5/AP.4.1.38. Connecting Rod Little End Bushes. There is a complaint from the Works regarding small pieces of BZ/PC. that get into the connecting rod and cannot be removed when the little end bush is pressed home and finally reamed in position. Their suggestion is that we use a semi-floating bush but we find that this was used some time ago and abandoned on account of wear on the rod and knocks. Will you please carry out the following experiment which should, if successful, help the Works in respect of this job. CASE (1) Little end bush F.51375 to have an external dia. exactly .001 larger than the bore of the rod. Record exactly the bore measurement of the bush. Warm up the rod to approx. 150°C. by immersion in oil, then insert the bush which should be free to push in. When cooled down, measure the bore of the bush to record what closing down has taken place. By this means it should be possible to allow for this closing down in the initial reaming of the bush. If satisfactory then there would be no occasion to touch the bush when in position in the rod and consequently no possibility of metal in the rod. CASE (2) Repeat of case (1) but with bush only .0005" larger in dia. than the rod bore. Will you please regard this as an urgent experiment and could be tried out on one of our endurance engines, if possible W.III. No.2. unit Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} | ||