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).
Re-tests of Condor engine connecting rods and the issue of whitemetal cracking in bearings.
| Identifier | ExFiles\Box 81\2\ scan0036 | |
| Date | 13th June 1919 | |
| To R.{Sir Henry Royce} from EH. c. to CJ. c. to BN.{W.O. Bentley / Mr Barrington} c. to E.{Mr Elliott - Chief Engineer} c. to Da.{Bernard Day - Chassis Design} EH4/LG13.6.19- 3495 X.3355 X.3415✔ X.2059 RE TESTS ON "CONDOR" CONNECTING RODS We have run the 2-cylinder "Condor" engine with the connection rod bearing made up as follows:- The connecting rod bush was set at 60°. The bush was lined with Hoyt No.11 whitemetal. The white-metalling was carried out by their expert at our works. There were 50% more oil holes in the bush. The bush had an annular groove; at the time this was fitted up we could not obtain one without. For the plain rod we ran with the bronze bush we have used previously. The bronze bush is sweated into the plain rod. We find on examination of the bearing that the white-metal has cracked in the top half of the bush. On the edges one can also see that the whitemetal is not adhering to the steel shell. The appearance of the bearing otherwise, is very good after this 10 hours run. We are now fixing into the connecting rods on the 2-cylinder "Condor" engine a bush having a greater number of small grooves for holding the whitemetal (R.R. whitemetal). The bush will have no annular groove and will be set at 60°. The trouble with whitemetalling of bearings has been with us the whole time we have made aero engines. Frequently 20 to 25% of connecting rod bearings on production engines were condemned by the A.I.D. after only 3 hours running because of | ||