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).
Blueprint graph showing power development for a 4 1/4 Litre Bentley cylinder head.
| Identifier | ExFiles\Box 148\5\ scan0113 | |
| Date | 1st September 1936 guessed | |
| 4 1/4 LITRE BENTLEY CYLINDER HEAD DEVELOPMENT POWER ① C/R 6.5:1 EX 22594 IN. VALVE 1.700 EX. VALVE 1.350 VALVE TIMING 'A' IN PORT 1.625 ② C/R 6.5:1 LEC 4123 IN. VALVE 1.750 EX VALVE 1.500 VALVE TIMING B IN PORT 1.625 TIMING 'B' I.O. 2° BT{Capt. J. S. Burt - Engineer} E.O. 51° BB I.C. 28° AB E.C. 7° AT TIMING 'A' I.O. 3° BT{Capt. J. S. Burt - Engineer} E.O. 52° EB I.C. 53° AB E.C. 6° AT AMAL. CARB. STRAIGHT ON TO IN. PORTS 1 11/16" THROTTLE BORE NOTE: THESE CURVES WERE COMPILED IN THE FOLLOWING MANNER:- ① FROM MAIN ENGINE RESULTS. 3.500 BORE UNIT COMP. RATIO CORRECTED FROM 9:1 ② FROM SINGLE CYLINDER RESULTS 3.25 BORE UNIT COMP. RATIO CORRECTED FROM C.17:1 B.H.P OBTAINED FROM B.M.E.P. CORR. TO 3.500 BORE UNIT .020 CLC B.H.P. B.M.E.P R.P.M. G.T.S G.328 Drawing Office Supplies Ltd. | ||