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 of piston displacement for crank angles with performance data from a Hispano engine test.
| Identifier | ExFiles\Box 180\M4\M4.2\ img009 | |
| Date | 25th February 1923 guessed | |
| 02 EXHAUST PEAKS RECORDED IF ONE PLUG ONLY IS USED Spring Used—Rating 91·5 Diagram Area Engine HISPANO Cyl. No. 6 Air Temp. 12°C Bar Temp. 765 Cooling Water Temp. 80°C R.P.M. 1500 Lbs. Lift 137 H.P. 8 I.M.E.P. 138 Lbs/sq in B.M.E.P. 112·0 Lbs/sq in Max. Expln. Pr.{Percy H. Rose} 465 Av. Expln. Pr.{Percy H. Rose} 4 Mechanical Efficiency. 81% Indicated Vol. Efficiency 98% FULL LINE 1" = 91·5 LBS/SQ in DOTTED LINE 1" = 62 LBS/SQ in EC IO IGNITION I.C.EO ATMOS. LINE PISTON DISPLACEMENT FOR CRANK ANGLES. | ||