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 the 20 HP engine's power increase due to long-duration valve lift, comparing standard and special camshafts.
| Identifier | WestWitteringFiles\Q\2April1927-June1927\ 120 | |
| Date | 23th May 1927 guessed | |
| 20 H.P. POWER INCREASE DUE TO LONG DURATION OF VALVE LIFT, WHEN USING THE STANDARD CARBURETTOR. ENGINE No. 11-GTC. COMPRESSION RATIO = 5.45 TO 1. LARGER VALVES (1.460 DIA) SPECIAL LONG DURATION CAMSHAFT. THE DOTTED CURVES REFER TO RESULTS OBTAINED WITH STANDARD CAMSHAFT (OTHER CONDITIONS BEING SIMILAR). BRAKE HORSE POWER B.H.P. B.M.E.P. BRAKE MEAN EFFECTIVE PRESSURE (LBS/sq in). R.P.M. OF ENGINE. | ||