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 (B.HP and B.M.E.P. vs R.P.M.) for different high lift rockers, valve lifts, and carburetors.
| Identifier | ExFiles\Box 182\M19\ img237 | |
| Date | 5th August 1931 guessed | |
| COMPARISON OF HIGH LIFT ROCKERS RM{William Robotham - Chief Engineer} P.20 SMALL VALVE HEAD 4.75 C/R INLET VALVE THROAT 1.680 114° CAMSHAFT E.83448 TIMING AS IN RM{William Robotham - Chief Engineer} P.19 --- VALVE LIFT .525 _ _ _ VALVE LIFT .470 CLAUDEL CARB. RR TWIN CHOKE CARB. 1.4 THROAT NO APPRECIABLE DIFFERENCE IN LOW SPEED M.E.P. WITH VALVE LIFT. B.H.P. 170 160 150 140 130 120 110 100 90 80 500 1000 1500 2000 2500 3000 3500 R.P.M. INDUCTION DEPN. INS. HG. B.M.E.P. LBS/SQ. IN. 110 100 90 80 70 3 2 1 | ||