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 showing the effect of increased valve lift on a 4.78 compression ratio engine.
| Identifier | Morton\M19\ img239 | |
| Date | 9th August 1931 guessed | |
| RM{William Robotham - Chief Engineer} P22 EFFECT OF INCREASED VALVE LIFT ON 4.78 C/R STD: CYLINDER HEAD 1.9" DIA. VALVE THROAT 114° CAMSHAFT TO E.82448 OPEN EXHAUST VALVE LIFT .525 VALVE LIFT .470 CLAUDEL TWIN CARBS 1.4" CHOKES B.H.P. R.P.M. B.M.E.P. LBS/SQ. IN. INDUCTION DEPN INS HG Valve Timing Diagram: EX 58, IN 54, 3, 12 | ||