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 power output with a 5.25 compression ratio using various carburettor and component configurations.
| Identifier | ExFiles\Box 13\4\ 04-page019 | |
| Date | 7th July 1928 | |
| RM.{William Robotham - Chief Engineer}P53 COMPARISON OF POWER OUTPUT WITH 5.25 COMP. RATIO 114° CAMSHAFT (E.{Mr Elliott - Chief Engineer} 82448) (LONG TYPE SILENCER - CUT-OUT OPEN) (DOUBLE VALVE SPRINGS) (STANDARD ROCKERS) ① STANDARD P.I. CARBURETTER AND INTAKE SILENCER ② SEMI - EXPANDING CARBURETTER AND INTAKE ③ 2 - 1 3/4 DIA S.U. CARBURETTERS, BALANCED BY 1/4 DIA. HOLE ④ SINGLE 2 1/2" BORE S.U. CARBURETTER B.H.P. B.M.E.P. LBS./SQ.IN. R.P.M. 7.7.28. /36 A.H.G. | ||