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 the petrol delivery rates of Autovac and Grav-Vac fuel feed systems at different engine speeds.
| Identifier | ExFiles\Box 40\4\ Scan233 | |
| Date | 28th March 1927 | |
| AUTOVAC AND GRAV-VAC PETROL FEED. TESTS CARRIED OUT ON A 20 H.P ENGINE WITH STANDARD CARBURETTOR AND INDUCTION PIPE. FUEL RAISED 32" THRO' A PLAIN PIPE .250" DIAM 6FT LONG. TESTS AT FULL AND HALF THROTTLE. LEGEND: GRAV-VAC : ----- (dashed line) AUTOVAC : _____ (solid line) Y-Axis: PETROL DELIVERY PTs/HR X-Axis: ENGINE R.P.M. CURVE LABELS & DATA POINTS: Top curves (Half Throttle): Induction Pipe Depression in Hg: 1.6", 2.25", 3.0", 3.9", 5.3" Bottom curves (Full Throttle): Induction Pipe Depression in Hg: 1.05", 1.25", 1.55", 1.6" | ||