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 the performance curves of standard and high-power Bentley engine units.
| Identifier | ExFiles\Box 134\2\ scan0110 | |
| Date | 13th February 1937 | |
| MAIN ENGINE BENTLEY. COMPARISON OF STANDARD AND HIGH POWER UNITS. ① STANDARD 3½ LITRE BENTLEY. ② HIGH POWER 3½ LITRE BENTLEY. ③ HIGH POWER 4¼ LITRE BENTLEY. COMPRESSION RATIO 6.4. VALVE SCALED UP IN SAME RATIO AS BORE. FIG. III B.M.E.P B.H.P R.P.M. J.L.E. | ||