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).
Letter concerning the failure of main bearings on a Bentley Chassis B.48.BN.
| Identifier | ExFiles\Box 27a\1\ Scan383 | |
| Date | 18th March 1936 | |
| To Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} Derby. Levallois Re: BENTLEY CHASSIS B.48.BN{W.O. Bentley / Mr Barrington} - Mr. ANDRIEU MAIN BEARINGS. Sr. has requested me to write to you concerning the small bits of white metal which the above owner said he found in the sump of his car and which Sr. spoke to you about on the telephone yesterday. We are sending you the bits of metal for your examination. As far as we can tell, it would appear that they have broken away from the side of one or more of the main bearings. For your information, we fitted a set of lead bronze bearings to this car on the 7.9.35, the car having then covered a total mileage of 19.250 Kms. We did not examine the main bearings. Up to the 5.12.35, this car had covered 22.582 Kms. We shall be glad to have your opinion as soon as you have had an opportunity of examining the bits of metal, as to whether you think that we should at once get hold of the car for the purpose of removing the bottom half and the caps of the main and intermediate bearings, for examination of the white metal. Sr. has informed me that, should we find the main bearings to be in a poor condition, you consider that we should fit a set of Halls metal main bearings. Therefore, in the event of your deciding that we should inspect the bearings, will you kindly arrange to have sent to us a set of Halls metal main bearings reamered and finished to size or as near to size as you think. We mention this because we do not possess a boring bar or reamers for this job. [Handwritten] We suggest that the internal dia: of the bearings should be .002" less than the Standard dia: of the main journals of the Crankshaft. [/Handwritten] As Sr. has probably told you, this gentleman is really a speed merchant and drives his car very hard. For you information, we have to-day dismantled the caps of the intermediate bearings of chassis B.118.BL (Mr. Spengler) and they were found to be quite O.K. (no signs of crack) after a mileage of 35.146 Kms. We did not remove the caps of the front, centre and rear main bearings as we thought it unnecessary in view of the condition of the intermediate bearings. This car is not driven so hard as chassis B.48.BN.{W.O. Bentley / Mr Barrington} In future, when we carry out an R.20 engine clean on Bentley cars or fit new big end bearings, we are going, at the same time, to inspect the main bearings. However, should we find the intermediate bearings to be in an O.K. condition, do you think it necessary to remove the caps of the front, centre and rear main bearings for inspection. As there is a doubt about the main bearings on certain Bentley chassis being in a reliable condition, especially on cars which are known to be driven for long distances at high speeds and which have covered say 20.000 to 25.000 miles, we think that it will be advisable for you to have sent to us a set of main bearings with | ||