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 curve graph for the 4 1/4 Litre Bentley Series II & III engines under various exhaust conditions.
| Identifier | ExFiles\Box 97\1\ scan0130 | |
| Date | 1st March 1938 | |
| 4 1/4 LITRE BENTLEY SERIES II & III POWER (1) STD. 4 1/4 LITRE BENTLEY OPEN EXH. (2) AS (1) WITH COMPLETE SILENCER SYSTEMS (3) BENTLEY III. OPEN EXH. (4) AS (3) BUT WITH SILENCER SYSTEMS AS (2) B.H.P. B.M.E.P. R.P.M. C.T.S. | ||