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 examination of a dismantled Bentley and Phantom III engine, detailing bearing and piston failures.
| Identifier | ExFiles\Box 91\3\ scan0160 | |
| Date | 31th October 1935 | |
| L.C. South 4700A HOTEL DE FRANCE. CHATEAUROUX. Indre. France. GWH{George W. Hancock - Head Chateauroux}/2/JAB. To. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} From. G.W.H. We have received your memo. of the 29th inst., We held up the Bentley yesterday the 30th and dismantled the Engine, a report of which I have sent to you. This held up Phantom III examination temporary. Having finished the Bentley, we dismantled the other connecting rods of Phantom III, and found that all the fork bearings were on the point of failure. We therefore telegraphed to you and were going to send A.B.Roberts to Derby with the bearings. Then T.Fisher arrived and from his information we understand that new bearings are on their way. In our opinion, the failure is due to the weakness of the bearings, possibly because of the abrupt change of section from the plate rod bearing, none of the plate rod bearings show any sign of failure. We shall send the bearings back with Fisher for your examination. We have examined all the bottom halves of the crank journal bearings. There is only N° 2 intermediate bearing which shows any sign of fracture. This bearing, the metal shows a fracture on the overlapping edge at the centre and also just inside. There are signs of the metal having been pushed forward. Underneath all these bearings, the Aluminum cap shows heavy punching effect between the bearing and cap. PISTONS. All Pistons have been examined. We cannot observe any sign of cracks. A peculiar feature is on Nos. 1 & 3 A - 2B. the top ring has broken approximately .875" from the slot end one scraper ring IA, the corner of the angle cut has broken off. The bedding of the Pistons is poor, none show a full bed on the skirts. The same symptoms as previously experienced on the Bentley. Re the Silent Tappets. We note your remarks re the excentric failure and shall send the remainder of the excentric back by T. Fisher. We do not quite understand your query re difference between the two sizes of plungers. The Engine was built up | ||