Graph comparing the power output of a standard 4¼ Litre Bentley engine with an Overhead Camshaft (O.H.C.) conversion unit.
| Identifier | ExFiles\Box 113\5\ scan0199 | |
| Date | 7th August 1937 guessed | |
| UNIT No. 23 4¼ LITRE BENTLEY POWER-OUTPUT. OVERHEAD CAMSHAFT CONVERSION UNIT. S.20 ① O-H-C. ENGINE. 6.5:1. COMP. RATIO. OPEN EXHAUST. (1a) As 1 BUT WITH STD. EXH. SILENCER. ② STANDARD 4¼ LITRE ENGINE OPEN EXHAUST. (2a) As 2 BUT WITH STD. EXH. SILENCER. B.H.P. B.M.E.P. R.P.M. C.T.S. | ||
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).