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).
Test report on a Bentley magnesium top half crankcase failure and potential for redesign.
| Identifier | ExFiles\Box 132\3\ scan0021 | |
| Date | 15th May 1934 | |
| X216 To SG.{Arthur F. Sidgreaves - MD} c. to Wor.{Arthur Wormald - General Works Manager} c. to E.{Mr Elliott - Chief Engineer} c. to By.{R.W. Bailey - Chief Engineer} c. to Bn.{W.O. Bentley / Mr Barrington} Magnesium Top Half Crankcase. We have tested the Bentley crankcase in magnesium. This case was run for 12 hours at 4000 R.P.M. full throttle and for half an hour at 4250 R.P.M. full throttle, when loss of oil pressure stopped the test. It was found that two of the bearings had broken away in the crankcase, as shown on the attached photographs, and most of the others were cracked. It was also noticed that the face where the two half crankcases join had fidgetted considerably. We think this test is most interesting as showing the weakest point of our present crankcase. We cannot say that a magnesium crankcase is impossible because they were used on the original Bentleys and raced. We believe that without a great deal of pattern modification we could make this material stand up, and think it is worth while for the Design Dept. to consider the necessary alterations. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||