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).
Seizure of big end bearings and related lubrication failures.
| Identifier | ExFiles\Box 115\1\ scan0158 | |
| Date | 3rd December 1936 | |
| Rm.{William Robotham - Chief Engineer} c to Rm{William Robotham - Chief Engineer}/GWH.{George W. Hancock - Head Chateauroux} P Des 1020 Swott- Hd{Mr Hayward/Mr Huddy}/SB{Mr Bull/Mr Bannister}15/HR.3.12.36. re SEIZURE OF BIG END BEARINGS. ------------------------- With reference to your Rm{William Robotham - Chief Engineer}9/R.1.12.36., enclosing copy of memo from GWH.{George W. Hancock - Head Chateauroux} in regard to failure of big end bearings, we would like to point out that the third paragraph of this memo is misleading. 1. We have looked up 12 cases of big end failures reported by K.{Mr Kilner}, and 11 of these were either Nos. 2 and/or 5, the other one being No. 6. Also, the majority of other failures dealt with by us have been Nos. 2 or 5. This fact alone points to the lubrication being at fault, since it is known that Nos. 2 and 5 big ends receive less oil than the others. A number of these connecting rods examined after return by K.{Mr Kilner} have shown more evidence of over-heating due to shortage of oil than merely breaking up. 2. We cannot understand why GWH.{George W. Hancock - Head Chateauroux} says that we have made a statement that we fit intermediate bearings with oil grooves whenever a failure has occurred. We presume the memo he refers to is Hd{Mr Hayward/Mr Huddy}/SB{Mr Bull/Mr Bannister}15/HR.26.11.36., in which we say that "although we make a point of fitting these bearings when we have occasion to dismantle the main bearings for any reason, it is rather a big job to tackle on say an R.10 or an R.20." You will agree that there is no question that a Depot Sheet should be issued instructing this modification whenever a seizure occurs. 3. K.{Mr Kilner} have had a copy of Hd{Mr Hayward/Mr Huddy}/SB{Mr Bull/Mr Bannister}4/HR.28.9.36., in respect of B.147-CW., an extract from which reads as follows, and we thought this would be sufficient intimation as to the procedure we adopt:- "We agree that when a convenient opportunity occurs the intermediate main bearings on -continued- | ||