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 intake manifold pressure and vacuum against engine RPM for supercharged and non-supercharged engines.
| Identifier | ExFiles\Box 178\2\ img152 | |
| Date | 4th April 1934 guessed | |
| INTAKE MANIFOLD PRESSURE 3 1/4 x 4 SUPERCHARGED ENGINE RATIO SUPERCHARGER TO CRANKSHAFT 5.76 : 1 INCHES OF MERCURY ATMOSPHERE LINE INTAKE MANIFOLD VACUUM 3 1/4 x 4 ENGINE NOT SUPERCHARGED CARBURETTER VACUUM 3 1/4 x 4 SUPERCHARGED ENGINE ENGINE R.P.M. PRESSURE VACUUM | ||