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 of three different Bentley cylinder head configurations against engine RPM.
| Identifier | ExFiles\Box 86\1\ scan0128 | |
| Date | 30th January 1935 | |
| COMPARISON OF CYLINDER HEADS. (BENTLEY) B.V. 73 UNIT B2 SPECIFICATION R.H.C./C.P 7/E P AEROLITE PISTONS H.1 (17.0 OZS.) ① CYLINDER HEAD E.B. 2050 (CLOSE CENTRE VALVES) COMPRESSION RATIO:- 7.0:1 INLET VALVE 1.500 DIA. EXHAUST VALVE 1.300 DIA. ② CYLINDER HEAD L.E.C. 3662 COMPRESSION RATIO:- 7.0:1 INLET VALVE 1.500 DIA. EXHAUST VALVE 1.200 DIA. OPEN EXHAUST NO AIR SILENCER ③ STANDARD CYLINDER HEAD COMPRESSION RATIO:- 6.43:1 INLET VALVE 1.400 DIA. EXHAUST VALVE 1.300 DIA. VALVE TIMING (.020 CLEARANCE) T.D.C. 8.3° 3.1° INL. EXH. 50-0° B.H.P. R.P.M B.M.E.P (LB/□") R.M / 18.2.35 | ||