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).
The failure of a No.2 Big End Bearing on car B.21.KU.
| Identifier | ExFiles\Box 114\3\ scan0016 | |
| Date | 17th February 1939 | |
| File. To By... from Rm{William Robotham - Chief Engineer}/GWH.{George W. Hancock - Head Chateauroux} c. Mx.{John H Maddocks - Chief Proving Officer} E.{Mr Elliott - Chief Engineer} Rm.{William Robotham - Chief Engineer} Re: Failure of No.2. Big End Bearing on B.21.KU - Lady Islington, after a mileage of 8,413. We are sending you No.5. con rod taken out of B.21.KU. as arranged by telephone. The history of this car is as follows: Was in the Depot in June 1938 for full modification at a milage of 11,475. The bearings were nipped up and rebored giving a maximum clearance of .003, min. .0025, crankshaft drilled. It has a large oil pump. The car so far as it is known is driven in town during the week, and at weekends it is the usual practice to go up to Oxford ( chauffeur's comments). It failed on the 15th.inst. whilst doing 90 m.p.h. The sump was full of oil. Examination of the bearings shew all the main bearings to be in an excellent condition. There was no lift in the crankshaft. Measuring up the con rod bearings which to all appearances are in an excellent condition, we found No.1.3.4. and 6 have retained the clearance as fitted, No.5. has lost its clearance and is on the tight side when on the crankpin. The crank pin dia. is 1.9980. The diameter of the bearing when fitted was 2.001". It now measures 1.9993" by gauges and micrometer. It has therefore decreased its clearance by .0017" leaving a diametrical clearance of .0013". This is a new problem to us and we should be grateful for your views. Rm{William Robotham - Chief Engineer}/GWH.{George W. Hancock - Head Chateauroux} | ||