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).
Performance graph comparing Brake Horse Power and Brake Mean Effective Pressure following the installation of larger valves on a 20 HP engine.
| Identifier | ExFiles\Box 5a\5\ 05-page041 | |
| Date | 31th March 1927 | |
| 20 HP POWER INCREASE DUE TO LARGER VALVES. ENGINE No 11-G.II. COMPRESSION RATIO = 5.45 TO 1 OPEN EXHAUST. Two ZENITH 1-1/16 VENTURI HORIZONTAL CARBURETTORS. CORRECTED TO N.T.P. 31-3-'27 B.H.P. LARGER VALVES (H.10064.) STANDARD VALVES (F.20076.) B.M.E.P. LARGER VALVES (H.10064.) STANDARD VALVES (F.20076.) BRAKE HORSE POWER BRAKE MEAN EFFECTIVE PRESSURE (LBS/SQ") R.P.M. OF ENGINE | ||