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).
Road test results and modifications for Bentley rear aluminium composite brake drums.
| Identifier | ExFiles\Box 85\1\ scan0009 | |
| Date | 24th January 1936 | |
| To RHC.{R. H. Coverley - Production Engineer} x256 Hs{Lord Ernest Hives - Chair}/AFM.{Anthony F. Martindale}11/KW.24.1.36. Bentley Rear Aluminium Composite Brake Drums. We have established during a road test that the above drums will never exceed 280°C., although a standard drum may reach 350°C., on a big bore Bentley. This means we can now try liners in less expensive materials, having lower expansion characteristics, with some hope of success. There are two rear aluminium castings not so far instructed. Will you please shrink into one of these a ring of Milenite with an interference fit of .026" - .028". The ring should have the same dimensions as those made previously, with fixings to Rm.{William Robotham - Chief Engineer}36, but we will omit the copper plating in this case, as the very high interference should assure good thermal contact. We hope you will be able to cut this liner out of a standard brake drum casting. One will be sufficient as we think it may crack, although the compression stress is not high, being 12 tons/sq." as a maximum. Hs{Lord Ernest Hives - Chair}/A.F.Martindale. | ||