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 comparing different camshaft configurations for a 4 1/4 Litre Bentley engine.
| Identifier | ExFiles\Box 90a\1\ Scan009 | |
| Date | 1st May 1937 | |
| 4 1/4 LITRE BENTLEY POWER DEVELOPMENT CAMSHAFT Report No 1 / May '37 56 B.3 UNIT CAMSHAFT Ex.22841 (WITH .750 RAD. FOLLOWERS) ON INLETS ONLY ① I.O 10° BT{Capt. J. S. Burt - Engineer} E.O 40° BB I.C 56° AB E.C 13° AT ② I.O 10° BT{Capt. J. S. Burt - Engineer} E.O 47° BB I.C 51° AB E.C 7° AT ③ I.O 10° 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 B.H.P B.M.E.P R.P.M | ||