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 engine performance (BHP, BMEP, Induction Depression) against RPM for two different compression ratios.
| Identifier | ExFiles\Box 14\3\ Scan076 | |
| Date | 8th December 1931 | |
| COMPARISON OF COMPRESSION RATIOS RM{William Robotham - Chief Engineer} P4G 114° CAMSHAFT E 82448 OPEN EXHAUST MANIFOLD ONLY STD VALVES 1.9 INLET THROAT. STD. ROCKERS RR TWIN CHOKE CARB. 1.4" DIA CHOKE COMPRESSION RATIO 5.22-1 COMPRESSION RATIO 4.65-1 B.H.P. 180 170 160 150 140 130 120 110 100 R.P.M. 500, 1000, 1500, 2000, 2500, 3000, 3500 B.M.E.P. LBS/SQ IN 120, 110, 100, 90, 80, 70, 60 INDUCTION DEPN. INS Hg 3, 2, 1 Valve Timing Diagram: 15 IN 55 013 CLCE EX 60.5 | ||