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).
Graph plotting the effect of inlet valve orifice coefficient improvements on engine performance during Bentley single-cylinder tests.
| Identifier | ExFiles\Box 133\2\ scan0091 | |
| Date | 5th January 1944 guessed | |
| BENTLEY SINGLE CYLINDER TESTS SHEET 8 EFFECT OF IMPROVEMENT OF INLET VALVE ORIFICE COEFFICIENT (SEE ALSO SHEET 7) Nº2 RAMP HEAD (L.C. 3871) NATURALLY ASPIRATED ZENITH TRIPLE DIFFUSER CARBURETTOR (32% CHOKE) OPEN EXHAUST VALVE TIMING TO GIVE MAXIMUM POWER AT 3000 R.P.M. WITHOUT LIMIT TO AMOUNT OF OVERLAP VIZ:- I.O. 14º E.{Mr Elliott - Chief Engineer} I.C. 36½º. E.O. 52º E.{Mr Elliott - Chief Engineer} E.C. 8º L. EXHAUST VALVE - 1.400" DIA AEROLITE PISTON FUEL = DTD 224 BRAKE HORSE POWER B.M.E.P. (LBS/SQ. IN.) R.P.M. CURVE 1 = INLET VALVE 1.500" DIA, COMP. RATIO = 6.5 CURVE 2 = INLET VALVE 1.600" DIA, COMP. RATIO = 6.5 CURVE 3 = INLET VALVE 1.600" DIA, VALVE GUIDE BOSS REMOVED FROM PORT & GUIDE REDUCED IN DIA. COMP. RATIO = 6.5 CURVE 4 = AS 3, BUT WITH AN EXTRA .050" RADIAL TREPANNING OF COMBUSTION CHAMBER AROUND INLET VALVE, THUS REDUCING THE COMPRESSION RATIO TO 6.25. | ||