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).
Performance graph comparing Mean Effective Pressure (MEP) against RPM for different Bentley engine timing and valve configurations.
| Identifier | ExFiles\Box 82\4\ scan0066 | |
| Date | 31th December 1934 guessed | |
| BENTLEY FILE x4553 MEP BEST TIMING AT 3000 RPM. I.O. 10°E E.O. 52°E I.C. 36°L E.C. 2°L STANDARD BENTLEY (1.400 IN., 1.300 EX, 1.350 PORT DIA) CLOSE CENTRES (1.500 IN., 1.400 EX, 1.500 PORT DIA) RAMP (1.500 IN., 1.400 EX, 1.500 PORT DIA) STANDARD TIMING I.O. 4°E E.O. 51°E I.C. 51°L E.C. 7°L R.P.M. | ||