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 different Bentley cylinder head configurations.
| Identifier | ExFiles\Box 86\1\ scan0143 | |
| Date | 30th January 1935 | |
| B.V. 78. COMPARISON OF CYLINDER HEADS (BENTLEY) UNIT:- B2 SPECIFICATION:- R.H.C/C.P. 7/E.P. 30-1-35 AEROLITE PISTONS H.1 (17.0 ozs.) ① CYLINDER HEAD E.B. 2050, 7.0:1 COMP. RATIO 1.500 DIA INLET VALVES, 1.300 EXHAUST VALVES. (CLOSE CENTRE VALVES) ② CYLINDER HEAD L.E C 3662, 7.0:1 COMP. RATIO 1.500 DIA INLET VALVES, 1.200 EXHAUST VALVES ③ As ② BUT WITH EXHAUST VALVES INCREASED TO 1.300 DIA. OPEN EXHAUST. NO AIR SILENCER. ④ As ③ BUT WITH TURBULENT LIP MACHINED TO E.x6041 ROUND INLET VALVES ONLY NOTE:- THESE CURVES WERE TAKEN AFTER THIS UNIT HAD COMPLETED 20 HOURS ENDURANCE ON E.B. 2050 CYL. HEAD VALVE TIMING (.020 CLEARANCE) T.O.C. EXH 8.3° INL 3.1° 50.8° 50.0° B.H.P. R.P.M. B.M.E.P. (LB/SQ") R.W.J/35 C/80 | ||