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 Autovac petrol delivery performance on a 20 HP engine at half throttle.
| Identifier | ExFiles\Box 40\4\ Scan218 | |
| Date | 2nd February 1927 guessed | |
| INDUCTION PIPE DEPRESSION (INS MERCURY) FIG II AUTOVAC COMPARISON TESTS. 20 H.P. ENGINE No 11GIII. STANDARD INDUCTION SYSTEM. TESTS AT HALF THROTTLE. PETROL LIFTED 32" THROUGH A PLAIN PIPE .250" BORE 6FT LONG. AUTOVAC PETROL DELIVERY (PTS/HR) ENGINE R.P.M. x AUTOVAC WITH MOVING FLOAT. o MEASURING AUTOVAC. Δ MEASURING AUTOVAC WITHOUT PETROL VALVE. □ STANDARD AUTOVAC. No DELIVERY BELOW 1000 R.P.M. | ||