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 showing 20HP engine power increase from modifications to compression, valves, and induction pipe.
| Identifier | WestWitteringFiles\Q\2April1927-June1927\ 12 | |
| Date | 23th May 1927 guessed | |
| 20HP POWER INCREASE DUE TO HIGHER COMPRESSION RATIO, LARGER VALVES AND LOWER DEPRESSION IN THE INDUCTION PIPE. ENGINE N° 11-GII OPEN EXHAUST CORRECTED N.T.P. BRAKE HORSE POWER B.H.P. B.M.E.P. 20 HP ENGINE WITH LARGE (1.400 DIA) VALVES, 5.45 TO 1 COMP. RATIO & TWO ZENITH TRIPLE VENTURI HORIZONTAL CARBURETTORS. B.H.P. B.M.E.P. STANDARD 20 H.P. (OPEN EXHT.) R.P.M. OF ENGINE BRAKE MEAN EFFECTIVE PRESSURE (LBS/☐") 4 | ||