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 showing power increase on a 20HP engine due to a special long duration camshaft compared to a standard camshaft.
| Identifier | ExFiles\Box 5a\5\ 05-page055 | |
| Date | 31th March 1927 guessed | |
| 20HP POWER INCREASE DUE TO LONG DURATION OF VALVE LIFT. ENGINE No 11-GII COMPRESSION RATIO = DIAG No 1 LARGER VALVES. (-NOT ON) TWO ZENITH TRIPLE DIFFUSER TYPE CARBURETTORS. SPECIAL LONG DURATION CAMSHAFT. THE HEAVY DOTTED CURVES SHOW RESULTS WITH STANDARD CAMSHAFT. (OTHER CONDITIONS SIMILAR) THE LIGHT DOTTED CURVES ARE A CONTINUATION OF THE FORMER, OWING TO A SLIGHTLY GREATER INDUCTION PIPE DEPRESSION DURING THE STD. CAMSHAFT TEST. B.H.P B.M.E.P BRAKE HORSE POWER BRAKE MEAN EFFECTIVE PRESSURE (LBS/SQ") R.P.M. OF ENGINE | ||