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).
Report concerning excessive sinkage of Hall's Metal main bearings for chassis B.48.BN.
| Identifier | ExFiles\Box 146\2\ scan0065 | |
| Date | 15th January 1937 | |
| To Dee SWDL{Len H. Swindell} To Bentley Motors Ltd. Derby............... Rm.{William Robotham - Chief Engineer} Copy to ............. Rm.{William Robotham - Chief Engineer} Levallois Sr/VA3/ET.15.1.37 Re: CHASSIS B.48.BN{W.O. Bentley / Mr Barrington} - Mr. ANDRIEU (Excessive sinkage of Hall's Metal main bearings) As the owner of this car is known to us as one of our "high speed merchants", we fitted a set of connecting rods with lead bronze bearings on the 7.9.35, after the car had covered 19.280 Kms. The car was sent to us for attention on the 14.4.36 after having covered a total mileage of 29.072 Kms. In view of the fact that this owner is a very fast driver, we thought it advisable to examine the lower halves of the main bearings. This we did and found the intermediate bearings to be in a very poor condition. We decided to change the bearings, especially as the car was fitted with lead bronze big ends. For your guidance, we fitted a set of Hall's metal main bearings to the following part numbers: 4 EB2811 Centre and front bearings 1 ea.EB2812/13 Rear bearings 4 ea.EB2814 & EB2809 Intermediate bearings } Sent by Works in case N° B.496. This car was involved in a bad accident last November, which necessitated removing the engine from the frame, etc... Since the fitting of the Hall's metal main bearings and up to the time of the accident, the car had covered 11.050 Kms. We therefore thought it would be a good opportunity of examining the main bearings for sinkage and, if necessary, carry out a tightening up job. Upon examination of the main bearings, we found them to be very slack in their housings, as the following report will show. You will observe that, on the upper halves of n° 2 and 7 bearings, we have recorded as much as .011" sinkage. We have had no alternative but to remove the main bearings and replace them by standard white metal bearings. R E P O R T - (Total mileage: 40.122 Kms.) CRANKSHAFT : 1 : 2 : 3 : 4 : 5 : 6 : 7 Maximum diameter of Journals....: 2"247 : 2"247 : 2"2465 : 2"2465 : 2"2465 : 2"2465 : 2"247 Minimum diameter of Journals....: 2"2465 : 2"2465 : 2"246 : 2"246 : 2"246 : 2"246 : 2"246 Ovality.....: .0005 : .0005 : .0005 : .0005 : .0005 : .0005 : .001 | ||