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).
Experimental testing of 25/30 connecting rods made direct from a new forging process.
| Identifier | ExFiles\Box 103\2\ scan0193 | |
| Date | 28th January 1937 | |
| Rm{William Robotham - Chief Engineer}/Smth. from Rm.{William Robotham - Chief Engineer} S.14 Rm{William Robotham - Chief Engineer}20/R.28.1.37. We want to test experimentally some 25/30 connecting rods made direct from the forging without the panel, milling, etc. which is at present in vogue. We think that the best way to get this job moving is to get a new die sunk by Hughes Johnson or the English Steel Corporation, and before doing so get them to guarantee a finished forging variation not more than a percentage with which we think we can cope. Rovers get over this variation by having selected assembly; they group rods in sets which have similar big end and small end weights. While we are on the job we think it is time that we considered throwing away shims between the cap and the connecting rod. It may be that the cost of this item is relatively insignificant, but you might ascertain this. In any case, if it is decided to throw these away the die will have to be modified accordingly, as the usual procedure is to broach an oval hole in the big end, cut the cap off the rod, fix the two pieces together, and then broach a round hole. Rm.{William Robotham - Chief Engineer} | ||