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).
Explaining the failure of a Bensport piston due to it being made from an unsuitable old crankcase alloy.
| Identifier | ExFiles\Box 86\2\ scan0020 | |
| Date | 27th March 1933 | |
| X 236 To R.{Sir Henry Royce} from E.{Mr Elliott - Chief Engineer} c. Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} Hs.{Lord Ernest Hives - Chair} By.{R.W. Bailey - Chief Engineer} E.1/HP.27.3.33. Bensport Piston. Since writing memo E.4/HP.25.3.33, we understand that by some mistake the Bensport piston which broke was made from our old crankcase alloy which should satisfactorily explain the failure, as this material is very weak at elevated temperatures, and unsuitable for pistons. By comparison with sandcast RR.53 it would have an ultimate of 3½ tons at about 300C as against 13 tons for the former. It also suggests why we have done so much running on 19-G-4 under almost similar conditions without experiencing any failure. The weight of the broken off portion of the piston mentioned in our memo E.4/HP.25.3.33 should have been given as point 5 lbs. The decimal point was inadvertently left out. E.{Mr Elliott - Chief Engineer} [Stamped: RECEIVED MAR 1933] | ||