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 increasing clearance around the inlet valve on engine performance with twin Zenith carburettors.
| Identifier | ExFiles\Box 102\1\ scan0041 | |
| Date | 1st January 1940 guessed | |
| R.M.47 EFFECT OF INCREASING CLEARANCE ROUND INLET VALVE JAPAN ON TWIN ZENITH CARBS. OPEN EXHAUST 112° CAMSHAFT E.55640 1.4" DIA. INLET VALVES TIMING TOO EARLY FOR MAX. POWER C/R 5.35 VALVE LIFT .344 B.H.P. B.M.E.P. RPM EX IN .013 CLCE 40 65 46 2 MIN. CLCE ROUND INLET VALVE .225" MIN. CLCE ROUND INLET VALVE .100" SEE SKETCH AS ABOVE BUT VALVE LIFT .395. | ||