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 comparing Bentley engine power development for the Tourist Trophy Races between 1934 and 1936.
| Identifier | ExFiles\Box 90a\1\ Scan003 | |
| Date | 28th September 1936 guessed | |
| BENTLEY POWER DEVELOPMENT 51 TOURIST TROPHY RACES COMPLETE WITH RACING EXHAUST SYSTEMS ① 1934 3 1/2 LITRE COMP. RATIO 7.75:1 50% BENZOL 50% SHELL No.1 ② 1935 3 1/2 LITRE COMP. RATIO 8.35:1 50% BENZOL 50% ESSO ETHYL ③ 1936 4 LITRE COMP. RATIO 9.0:1 ESSO ETHYL B H P R P M O.T.S. | ||