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 from 20 HP experiments showing the effect of large valves and long duration cams on power output.
| Identifier | ExFiles\Box 69\4\ scan0371 | |
| Date | 26th May 1927 | |
| 20 H.P.R.R. EXPERIMENTS. CURVES SHEWING THE EFFECT OF LARGE VALVES AND LONG DURATION CAMS ON THE POWER OUTPUT. SEE REPORTS ON 20 H.P. CAMSHAFT EXPTS. 23-5-27 AND 26-5-27. B.H.P. 90 80 70 60 50 40 LARGE VALVES AND LONG DURATION INLET & EXHAUST CAMS. VALVE AREA INCREASED BY 40% STANDARD. R.P.M 1500 2000 2500 3000 3500. No.4. OWP | ||