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 timing overlap on the power of a standard Bentley single-cylinder head.
| Identifier | ExFiles\Box 133\2\ scan0123 | |
| Date | 1st November 1934 guessed | |
| BENTLEY SINGLE CYLINDER TESTS. EFFECT ON POWER OF VALVE TIMING OVERLAP (STD. BENTLEY HEAD). SHEET 4 STANDARD BENTLEY CYLINDER HEAD (EB1517). COMPRESSION RATIO = 6:4 INLET VALVE = 1.400 DIA, EXHAUST VALVE = 1.300 DIA. AEROLITE PISTON ZENITH TRIPLE DIFFUSER CARBURETTOR (32 m/m CHOKE) OPEN EXHAUST NATURALLY ASPIRATED FUEL - DTD 224. BRAKE HORSE POWER B.M.E.P. (LBS/SQ. IN.) R.P.M. TABLE DATA: CURVE, TIMING, I.O., I.C., E.O., E.C., OVERLAP 1, NORMAL BENTLEY, 4° E, 51° L, 51° E, 7° L, 11° 2, , 2° E, 51° L, 51° E, 4° L, 6° 3, , 1° L, 51° L, 51° E, 1° L, 0° 4, BEST AT 3000, 10° E, 37° L, 53° E, 2° L, 12° 5, , 7° E, 37° L, 53° E, 1° E, 6° 6, , 4° E, 37° L, 53° E, 4° E, 0° NOTE: TO PREVENT CRAMPING, THE B.H.P CURVES Nos. 2 & 5 ARE NOT CONTINUED DOWN TO THE LOWER ENGINE SPEEDS. | ||