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).
Performance graph comparing a Twin Zenith carburettor against a Standard carburettor with different camshaft configurations.
| Identifier | ExFiles\Box 102\5\ scan0061 | |
| Date | 11th July 1930 | |
| TWIN ZENITH CARBURETTER ON (JAPAN IV G6) V914 COMPARISON WITH STD CARBURETTER. ZENITH RUN WITH 26 m/m CHOKES. SMALL BORE INDUCTION PIPE COMPLETE STANDARD 25HP EXHAUST SILENCING SYSTEM. STANDARD 110° AND LONG DURATION 112° CAMSHAFTS 5.25:1 COMPRESSION RATIO BHP RPM MEP Graph Labels: TWIN ZENITH 112° CAMSHAFT TWIN ZENITH 110° CAMSHAFT STD CARB 112° CAMSHAFT STD CARB 110° CAMSHAFT TWIN ZENITH 112° CAMSHAFT Initials: W.B. | ||