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 plotting the mechanical efficiency versus RPM for a 3½ Litre Bentley engine.
| Identifier | ExFiles\Box 133\1\ scan0209 | |
| Date | 27th January 1934 | |
| 3½ LITRE BENTLEY C.75 Fig IV MECHANICAL EFFICIENCY INDUCTION SYSTEM: 1¾" SU CARBS AND STANDARD INDUCTION PIPE. EXHAUST SYSTEM: STANDARD TEST BED SYSTEM. CYLINDER HEAD: STANDARD 3½ LITRE BENTLEY HEAD. INLET VALVE: 1.400" DIA. EXHAUST VALVE: 1.300" DIA. COMPRESSION RATIO: 6.4:1 FUEL: D.T.D. 224 VALVE TIMING: I.O. 4°E E.O. 51°E I.C. 51°L E.C. 7°L WATER TEMPERATURES: INLET 78°C OUTLET 85°C OIL TEMPERATURE: INLET 80°C. MECHANICAL EFFICIENCIES ① BY CUTTING OUT CYLINDERS (—) ② STRAIGHT MOTORING BY B.T.H. MOTOR (---) MECHANICAL EFFICIENCY (%) - R.P.M. - C.75/2 ED{J. L. Edwards} 27.1.34 | ||