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 comparing the performance of a standard cylinder head against a high compression cylinder head.
| Identifier | ExFiles\Box 82\4\ scan0052 | |
| Date | 31th August 1934 | |
| B.V. 47 COMPARISON OF CYLINDER HEADS UNIT: B.3. SPECIFICATION:- R.H.C. / W.S.C. 10 / E.P. 31-8-34. NO AIR INTAKE FITTED. OPEN EXHAUST. DOTTED LINE REPRESENTS STANDARD CYL. HEAD WITH STANDARD VALVE SPRINGS C.R.= 6.47:1 FULL LINE REPRESENTS HIGH COMPRESSION CYL. HEAD WITH 1.500 DIA. INLET VALVES, 1.200 DIA. EXHAUST VALVE & E.B. 507/B DOUBLE VALVE SPRINGS, C.R. = 6.95:1 VALVE TIMING (.020 CLEARANCE) T.D.C. 32° 7.9° INL. 49.0° EXH. 50.4° B.H.P. R.P.M. B.M.E.P. (LB/SQ") | ||