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).
Graph comparing motoring losses for a 4¼ Litre Bentley engine with a standard block versus one with chromium-plated bores.
| Identifier | ExFiles\Box 133\1\ scan0208 | |
| Date | 7th April 1937 | |
| 4¼ LITRE BENTLEY COMPARISON OF MOTORING LOSSES FIG III C. 74 ① STANDARD 4¼ LITRE ENGINE WITH STANDARD BLOCK AND PISTONS. ② STANDARD 4¼ LITRE ENGINE WITH CHROMIUM PLATED BORES. THE PISTON CLEARANCES WERE KEPT STANDARD BY FITTING SMALLER PISTONS. L.H.P. AND L.M.E.P. R.P.M. L.H.P L.M.E.P ED.{J. L. Edwards} 7.4.37 | ||