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).
Power development graph for a 4¼ Litre Bentley engine, testing different camshaft configurations.
| Identifier | ExFiles\Box 82\4\ scan0393 | |
| Date | 1st October 1936 guessed | |
| 4¼ LITRE BENTLEY S.G / 6 POWER DEVELOPMENT CAMSHAFT B.3 UNIT CAMSHAFT Ex.82841 (WITH .750 RAD FOLLOWERS) ON INLETS ONLY. ① I.O 13° BT{Capt. J. S. Burt - Engineer} E.O 40° BB I.C 56° AB E.C 13° AT ② I.O 21° BT{Capt. J. S. Burt - Engineer} E.O 47° BB I.C 51° AB E.C 7° AT ③ I.O 3° BT{Capt. J. S. Burt - Engineer} E.O 47° BB } STD CAMSHAFT I.C 51° AB E.C 6° AT } WITH STD FOLLOWERS TIMINGS TAKEN @ .020 CLR BHP BMEP RPM ETS | ||