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 (BHP vs RPM) for a 4¼ Litre Bentley with different camshafts.
| Identifier | ExFiles\Box 90a\1\ Scan010 | |
| Date | 28th September 1936 guessed | |
| 4¼ LITRE BENTLEY POWER DEVELOPMENT CAMSHAFT S.7 CAMSHAFT EX 22842 (WITH .750 RAD. FOLLOWERS) ① I.O. 20° BT{Capt. J. S. Burt - Engineer} E.o. 44 BB I.C. 48° AB E.C. 19° AT ② I.O. 18° BT{Capt. J. S. Burt - Engineer} E.o. 40° BB I.C. 50° AB E.C. 28° AT ③ I.O. 8° BT{Capt. J. S. Burt - Engineer} E.o. 47° BB I.C. 37° AB E.C. 6° AT STD CAMSHAFT WITH STD FOLLOWERS BHP R.P.M. B.M.E.P CJS | ||