Graph showing the 20HP engine power increase due to modifications including higher compression, larger valves, and lower induction pipe depression.
| Identifier | ExFiles\Box 5a\5\ 05-page043 | |
| Date | 31th March 1927 guessed | |
| 20HP POWER INCREASE DUE TO HIGHER COMPRESSION RATIO, LARGER VALVES AND LOWER DEPRESSION IN THE INDUCTION PIPE. ENGINE NO. 11-G-II OPEN EXHAUST CONVERTED F.I.P. B.H.P. B.M.E.P. 20 HP ENGINE WITH LARGE (1.625 DIA) VALVES, 5.45 TO 1 COMP. RATIO & Two ZENITH TYPE VERTICAL-HORIZONTAL CARBURETTORS B.H.P. B.M.E.P. STANDARD 20 HP (OVER PAGE) BRAKE HORSE POWER. R.P.M OF ENGINE BRAKE MEAN EFFECTIVE PRESSURE (LBS/SQ") 4 | ||
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).