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 performance and back pressure of five different exhaust systems against engine RPM.
| Identifier | ExFiles\Box 5a\5\ 05-page152 | |
| Date | 11th August 1931 | |
| RM{William Robotham - Chief Engineer} 26 COMPARISON OF EXHAUST SYSTEMS. CHINA. J12 SHAFT HIGH LIFT ROCKERS. 5.65 C/R STD 15% LARGER CARB. ① OPEN EX. ② PII EX. SYSTEM ③ W.W. Mch. 3256 Fd{Frank Dodd - Bodies} FISHTAIL ④ W.W. Mch. 3256 25HP FISHTAIL ⑤ STD 25 H.P. SYSTEM ARRGt E.55794 B.H.P. EXHAUST BACK PRESSURE InS. HG. R.P.M. 11-8-31 | ||