Blueprint graph comparing the airflow of a standard head versus a large inlet valve head for the Phantom engine.
| Identifier | ExFiles\Box 31\2\ Scan112 | |
| Date | 29th August 1933 guessed | |
| PHANTOM. CURVE 1. FLOW THRU PORT CU.FT./MIN COMPARISON OF STANDARD HEAD - E.83538 & LARGE INLET VALVE HEAD - E.83906 AT 1/3 VALVE LIFT - i.e. .160" LIFT PRESS. DIFFERENCE ACROSS VALVE - "Hg" (1) —— STD. HEAD. E.83538 (2) —— LARGE VALVE HEAD - E.83906 | ||
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).