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 inlet valve displacement against piston displacement for 'Hispano' and 'E.A.C.' configurations.
| Identifier | Morton\M4.2\ img014 | |
| Date | 1st January 1923 guessed | |
| INLET VALVE DISPLACEMENT. ON PISTON DISPLACEMENT BASE. TOP CENTRE BOTTOM CENTRE. HISPANO E.A.C. STROKE PISTON DISPLACEMENT FROM IN CENTRE. .50 .40 .30 .20 .10 0 1 2 3 4 5 5.5 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 225° | ||