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).
Analysis of a connecting rod failure on chassis B.51-AE.
| Identifier | ExFiles\Box 89\3\ scan0061 | |
| Date | 25th September 1935 | |
| Hd{Mr Hayward/Mr Huddy} C. K.{Mr Kilner} c. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} x 261 BY.7/G.25.9.35. Rm{William Robotham - Chief Engineer} RE: CHASSIS NO. B.51-AE. STEWART. CONNECTING ROD FAILURE. -------------------- Hd{Mr Hayward/Mr Huddy}/SB.{Mr Bull/Mr Bannister}5/HR.19.9.35. Referring to the No.2 big end which failed on the above chassis, from an examination of the three rods which you sent me for this purpose I cannot find that there is anything wrong with the metalling, in fact, considering the length of time the engine was run they appear to me to be in quite good condition, bearing in mind that it is a Bentley car under discussion and not a 20/25. Apparently a failure of this type can take place with white metal and sufficient warning be given to the owner to prevent serious damage, and this aspect of the matter is rather comforting, although one is not certain whether it would regularly happen this way. From an examination of a bearing I am inclined to think that the owner may possibly have run the quantity of oil in the sump to a minimum, under which circumstances No.2 and No.5 bearings would show signs of trouble first, and this is precisely what has happened as No.5 which is one of the three returned to me is certainly the worst of the three, and furthermore there are one or two small pieces of aluminium swarf in the bearing which might point to a depleted oil sump, when, of course, any deposited matter would be much more liable to be drawn into the pumps; the evidence, however, is not sufficient to justify us raising the issue again. Will you kindly collect the three rods, as they are in good condition and can be used again. By BY.{R.W. Bailey - Chief Engineer} | ||