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).
List of weights for different valve types for J.III type dampers.
| Identifier | ExFiles\Box 105\3\ scan0311 | |
| Date | 23th January 1933 | |
| X5520. Copy for files. 23.1.33. WEIGHT OF THE VALVES FOR J.III TYPE DAMPERS. x4538. Steel with alum damping disc F.59306 = 12.95 grms. All steel F.100695. = 18.6 grms. All steel lightened Hs.{Lord Ernest Hives - Chair}909. = 14.2 grms. All duralumin lightened Hs.{Lord Ernest Hives - Chair}909. - 5 grms. Hs{Lord Ernest Hives - Chair}/Les.{Ivan A. Leslie} | ||