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).
Performance and issues with Bentley engine bearings and petrol pumps.
| Identifier | ExFiles\Box 146\3\ scan0162 | |
| Date | 4th February 1936 | |
| Bentley Motors (1931) Ltd., DERBY.....................Rm.{William Robotham - Chief Engineer} Srl/Crn.4.II.36. Bentley engine bearings. I wish to acknowledge receipt of your memoranda Rm.{William Robotham - Chief Engineer}7/AP.29.IO.36 and Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell}29/JH.30.IO.36, both of which were very interesting to read. I am not yet quite satisfied in my own mind that the Hall metal bearings on the 4 1/4 litre will go on for considerably longer than, for instance, those dismantled from B. 60 GA, and the point is how much longer after the vibration period sets in do you think it would be safe to let customers run their cars prior to dismantling ? WHA reports that the first 4 1/4 litre on the road over here, belonging to M.{Mr Moon / Mr Moore} Patrick Le Blan, which has now covered 18,000 kilometres, is just about as rough as B. 60 GA. We are naturally anxious that this customer should not run into bearing troubles. The mileage, as you will note, is approximately that at which our cars began to shew signs of trouble. The bearings now fitted to B. 60 GA are white metal mains, and Halls big ends. Incidentally, proper attention was taken to ensure that any score marks in the crank main bearings were lapped before fitting the white metal. You need, therefore, have no fear from this source, and we will be on the road with the car to-morrow. From this time onwards, we will make every effort to keep it running, so as to get some information as rapidly as possible. The other figures concerning measurements taken on B. 60 GA were also of interest. I am beginning to think that at some time or other, we shall have to let one of our cars (if we have one fitted with Halls metal) run itself properly out, so as to ascertain until when these bearings, which are not considered bad by your department, really "stay put". However, I cannot forget my own car, B. 8 GA. There was certainly no possibility of running this car any longer, as GWH{George W. Hancock - Head Chateauroux} will be able to confirm. You will be glad to hear that B.8 GA is now running very well indeed, being free from periods of any description. Incidentally, when GWH{George W. Hancock - Head Chateauroux} was last here he fitted a petrol pump which I understand is an improved type. Up to this moment, the pump is behaving exceedingly well, being free from any rattles, and the car starts up in the morning without any effort. We, however, experience trouble with quite a few later type pumps (not like mine, which I understand is very special). Now the weather is cold, people cannot get started up in the mornings, owing, I presume, to the diaphragm becoming too taught, and refusing to pulsate. .................. | ||