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).
Performance graph comparing large and small valves, plotting Brake Horsepower (BHP) and Brake Mean Effective Pressure (BMEP) against engine RPM.
| Identifier | ExFiles\Box 182\M19\ img236 | |
| Date | 20th August 1931 | |
| RM.{William Robotham - Chief Engineer} P.15 COMPARISON OF LARGE & SMALL VALVES 4.78 C.R. W.W. 1 1/4" SHAFT LEG 2818 OPEN EXHAUST INS. OPEN 3000 RPM LARGE VALVES C DENOTES CLAUDEL 1:90 T TWIN CARB 1.4 DIA CHOKE 2:55 Valve Timing Diagram: Ex 32, IN 61.8, 10, 5, 013 CLCE B.H.P. B.M.E.P. LBS/SQ.IN RPM ① INLET VALVE THROAT 2.00 TREPANNED ROUND PORTS. ② INLET VALVE THROAT 1.680 30° SEAT Hs.{Lord Ernest Hives - Chair}372 Curve Labels: ①C, ②C, ①T, ②T | ||