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 Twin Zenith and standard carburetters with 110° and 112° camshafts.
| Identifier | ExFiles\Box 13\2\ 02-page074 | |
| Date | 11th July 1930 | |
| TWIN ZENITH CARBURETTER ON (JAPAN IVG6) V914 COMPARISON WITH STD CARBURETTER ZENITH RUN WITH 26"L-CHOKES SMALL BORE INDUCTION PIPE COMPLETE STANDARD 26HP EXHAUST SILENCING SYSTEM STANDARD 110° AND LONG DURATION 112° CAMSHAFTS 5.25:1 COMPRESSION RATIO BHP RPM Curve Labels: TWIN ZENITH 112° CAMSHAFT TWIN ZENITH 110° CAMSHAFT STD CARB 112° CAMSHAFT STD CARB 110° CAMSHAFT TWIN ZENITH 112° CAMSHAFT STD CARB 112° CAMSHAFT STD CARB 110° CAMSHAFT TWIN ZENITH 110° CAMSHAFT Handwritten: W.O.S 11-7-30 | ||