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 BHP and BMEP for a 20 HP engine with standard versus larger valves and different carburetors.
| Identifier | WestWitteringFiles\Q\2April1927-June1927\ 11 | |
| Date | 31th March 1927 | |
| 20H.P. POWER INCREASE DUE TO LARGER VALVES AND LOWER DEPRESSION IN THE INDUCTION PIPE. ENGINE No 11-GII COMPRESSION RATIO = 5.45 to 1. OPEN EXHAUST. CORRECTED TO N.T.P. 31-3-27 BRAKE HORSE POWER BRAKE MEAN EFFECTIVE PRESSURE (LBS/SQ") R.P.M. of ENGINE. B.H.P. B.M.E.P. LARGE VALVES (1.400 DIA) AND TWO ZENITH TRIPLE VENTURI HORIZONTAL CARBURETTORS. B.H.P. B.M.E.P. STANDARD VALVES (1.200 DIA) AND R.R. CARBURETTOR. 3 | ||