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).
Engine bearing trouble and comparing different types of bearings such as white metal, Hall's metal, and lead bronze.
| Identifier | ExFiles\Box 146\3\ scan0076 | |
| Date | 5th September 1936 | |
| Another case of engine trouble has just been telephoned through from Tours and, from the owner's remarks, it would appear that it is also bearing trouble. The car is being sent to us for attention. As the mileage of this particular car (viz. chassis B.5.AE) is fairly high, it may be a case of fair wear and tear, although the big end bearings have been changed once and the present set have not covered more than 18.000 miles. What I am seriously concerned about is that I am convinced that the bearings of any amount of Bentley cars out here, which have done a comparatively small mileage, must be in a very poor condition. This being the case, we must naturally expect failures if we do not immediately get back to some system whereby cars are called in and their bearings changed for bearings that will give a reasonable life and not white metal or first type Hall's metal bearings; the latter, I am afraid from previous experience, being worse than the white metal bearings. You will agree with me that it is going to be extremely expensive for the Company if we are to pull down engines and fit them with a different type bearing, which to all intents and purposes is worse than the original white metal bearings with which they were fitted. This unfortunately would appear to be the case with three or four cars fitted with first type Hall's metal bearings, if we take as an example the condition of all bearings on B.8.GA. From our experience, the lead bronze bearings, apart from the oil consumption, have undoubtedly proved, up to date, to be the most reliable big end bearings for continental conditions. These bearings, fitted in conjunction with an improved type piston ring, would seem to me to be the solution as, when one goes thoroughly into the question, it would appear that, when a car fitted with Hall's metal bearings is driven to capacity, the oil consumption is not what one might exactly call low and the customers who are using cars fitted with lead bronze bearings, and who incidentally are our biggest "batters", admit that the oil consumption is high, but do not complain about it. We only had one case where the customer's complaint had to be dealt with. I have not as yet dealt with the question of main bearings, but it is evident, always judging from the state of our demonstration car, that where the original type Hall's metal has been fitted to the main and big end bearings, these engines will have to come down and this, as you will realise, is a big job. When it is only a case of big end bearings it is not an impossible task to slip in a new set of bearings, but it really becomes a big job when one has to take out the engine and strip it to replace intermediate or main bearings. Finally, the object of this memo is to ask you kindly to give us rapidly a ruling on our future method of operation with regard to the above mentioned. In my opinion, we must no longer wait until the cars crack up on the road, as such publicity is the worst of its type, especially in view of the fact that we know that, up to the present, we have not got a bearing that will stand up to Continental conditions, with the exception of the lead bronze bearing and, it would appear, the latest type of Hall's metal bear- | ||