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 output graph comparing two engine configurations for the 3½ Litre Bentley.
| Identifier | ExFiles\Box 86\2\ scan0196 | |
| Date | 12th February 1933 | |
| UNIT B.48 3½ LITRE BENTLEY POWER OUTPUT SPEC (1) COMP RATIO 6.45:1 (EB-615) IN VALVE EB/64 (1.400 DIA) EX " EB/65 (1.300 DIA) (2) COMP RATIO 6.86:1 (LEC3662) IN VALVE EX/2089 (1.500 DIA) EX " EB/325 (1.200 DIA) STANDARD PISTONS B.H.P. B.M.E.P R.P.M. T.D.C. 36° 53° IN EX 49½° B.D.C. TAPPETS @ .020 | ||