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 curves graph showing BHP and BMEP vs RPM from a 10,000-mile engine test with various exhaust configurations.
| Identifier | Morton\M13.2\ img125 | |
| Date | 25th October 1931 | |
| POWER CURVES UNIT FOR 10,000 MILES TEST 18 G.IV C.XI C/R 5.7 CAMSHAFT Sch: 1542/3 STANDARD CARB: 15% LARGER ① OPEN EXHAUST ② COMPLETE P.II SHORT TYPE EX. SYSTEM ④ N.Sch 3285/6/7 WITH FISH TAIL EXIT OPENED TO P.II SIZE ③ As 4a FISHTAIL REMOVED ⑤ EXISTING STANDARD UNIT OPEN EXHAUST VALVES BOUNCE 3875 R.P.M. B.H.P. B.M.E.P. LBS/SQ IN R.P.M. 25/10/31. RM.{William Robotham - Chief Engineer} 49 | ||