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).
Grand Prix results, engine bearing performance, and fuel pump location issues.
| Identifier | ExFiles\Box 146\3\ scan0022 | |
| Date | 30th June 1936 | |
| W/P - Sr. <1245> Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}11/KW.30.6.36. Dear Sr., I was interested to see the result of the Grand Prix and that the Bugatti won. I asked Croydon over the 'phone if he would let me have photographs of the car, and at the same time I should be very interested to know whether Bugatti's have succeeded in increasing their top speed by streamlining. We want to get some information on the Hall's metal aluminium-tin bearings which have now covered a considerable mileage on your trials car. The story regarding these bearings is as follows. The original bearings ran 100 hours on the test bed and finished in perfect condition. 100 hours on the test bed is equal to about 75,000 miles on the road. Endurance tests we have recently run showed, to our surprise, that the Hall's metal bearings as being fitted to production have begun to hammer out of shape after 25 hours' running. On checking up we found that they had got wrong with the Brinell and these bearings are too soft. The matter has now been corrected but we are interested to know what is happening to these somewhat soft bearings in service. Your demonstration car has probably had more batting than any other, and for this reason we have asked Hancock to examine a big end if and when the opportunity occurs, and if this is in bad shape we may send you out a complete set of mains and big ends. Incidentally at 30,000 Kms. you should really look at your main bearings, or at least do an oil test on them because, if they get badly scored, a point may be reached where the big end bearings do not get sufficient oil, and when this happens the connecting rod comes through the crankcase as on B-23-AE. Do not get unnecessarily alarmed about this job; at the worst it is only on a par with white metal failures which have taken place in extreme cases in the past. We should be interested to know whether you experience any trouble with pump noise or vapour lock now that the filter is fitted on the back of the frame, on the Bentley. It appears that on the Ph.III, owing to high under-bonnet temperature, we shall have to move the pumps from the dashboard to the frame for cars sold to Continental owners. We shall have to develop a new pump because neither the S.U. nor the Autoflux will give us the supply we require with the increased head of 2'. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||