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 plotting inlet valve displacement against piston displacement, comparing 'Hispano' and 'E.A.C.' curves.
| Identifier | ExFiles\Box 180\M4\M4.2\ img014 | |
| Date | 25th February 1923 guessed | |
| INLET VALVE DISPLACEMENT. ON PISTON DISPLACEMENT BASE. TOP CENTRE .50 .40 .30 .20 .10 0 HISPANO E.A.C. PISTON DISPLACEMENT FROM IN CENTRE STROKE BOTTOM CENTRE 225° | ||