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 showing the effect of valve orifice coefficient improvements from Bentley single cylinder tests.
| Identifier | ExFiles\Box 133\2\ scan0122 | |
| Date | 1st November 1934 guessed | |
| BENTLEY SINGLE CYLINDER TESTS SHEET 3 EFFECT OF IMPROVEMENT OF VALVE ORIFICE COEFFICIENT (SEE ALSO SHEET 2) 'CLOSE-CENTRES' HEAD (L.C.4100) AEROLITE PISTON ZENITH TRIPLE DIFFUSER CARBURETTOR (32 m/m CHOKE) OPEN EXHAUST FUEL = DTD 224 VALVES TIMED FOR MAX. POWER AT 3000 R.P.M. (OVERLAP LIMITED TO 12°) 3 & 4 TO 3500 RPM. BRAKE HORSE POWER B.M.E.P. (LBS./SQ.IN.) R.P.M CURVE 1 = INLET VALVE 1.4 DIA; EXHAUST 1.25 DIA; C.R.=6.5 CURVE 2 = INLET VALVE 1.4 DIA; EXHAUST 1.3 DIA; C.R.=6.5 CURVE 3 = INLET VALVE 1.5 DIA; EXHAUST 1.3 DIA; C.R.=6.35 CURVE 4 = INLET VALVE 1.5 DIA; EXHAUST 1.4 DIA; C.R.=6.35 CURVE 5 = AS 4, BUT WITH INLET PORT ENLARGED TO 1.5 DIA, & VALVE GUIDE BOSS REMOVED. | ||