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.
| Identifier | ExFiles\Box 133\2\ scan0090 | |
| Date | 5th January 1944 guessed | |
| BENTLEY SINGLE CYLINDER TESTS SHEET 7 EFFECT OF IMPROVEMENT OF INLET VALVE ORIFICE COEFFICIENT (SEE ALSO SHEET 8) TEST PARAMETERS: No 2 RAMP HEAD (L.C.3871) NATURALLY ASPIRATED ZENITH TRIPLE DIFFUSER CARBURETTOR (32 m/m CHOKE) OPEN EXHAUST VALVE TIMING TO GIVE MAXIMUM POWER AT 3000 RPM BUT OVERLAP LIMITED TO 12° VIZ:- I.O. 10°E.{Mr Elliott - Chief Engineer} I.C. 37°L. E.O. 53°E.{Mr Elliott - Chief Engineer} E.C. 2°L. EXHAUST VALVE 1.400 DIA. AEROLITE PISTON FUEL - DTD 224 CURVE DESCRIPTIONS: 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 6.45 AXIS LABELS: LEFT Y-AXIS: BRAKE HORSE POWER RIGHT Y-AXIS: B.M.E.P. (LBS / SQ. IN.) X-AXIS: R.P.M. | ||