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 performance (BHP vs RPM) of twin carburettor setups with different choke sizes against a standard carburettor system.
| Identifier | Morton\M19\ img235 | |
| Date | 20th January 1931 | |
| TWIN R-R- CARBS AND INDUCTION SYSTEM COMPARISON WITH STANDARD PI CARBURETTOR AND INDUCTION SYSTEM TEST BED EXHAUST SYSTEM V1023 BHP 120 110 100 90 80 70 60 50 40 RPM 1000 1500 2000 2500 3000 TWIN CARBS 1.300 CHOKE TWIN CARBS 1.25 DIA CHOKES TWIN CARBS 1.35 DIA CHOKES STANDARD PI CARB. INDUCTION HHP 20-1-31 | ||