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).
Graph comparing the power output of a Bentley III engine using different induction and exhaust systems.
| Identifier | ExFiles\Box 108\2\ scan0200 | |
| Date | 16th January 1939 guessed | |
| INDUCTION SYSTEM COMPARISON BENTLEY III POWER "ETHYL" PETROL COMP RATIO 6.6 : 1 CAMSHAFT ExS. 759 (TIMING @ .030 CLCE) I.O 5.5' AT E.O 37° B.B I.C 50° AB. E.C 4.5° AT 1 B III INDN. SYSTEM 2 WRAITH INDN. SYSTEM a OPEN EXHAUST b SILENCED (B III EXH SYSTEM COMPLETE) R.P.M. 1a 2a 1b 2b | ||