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 for a Hispano engine, plotting pressure curves against piston displacement for various crank angles.
| Identifier | Morton\M4.2\ img009 | |
| Date | 1st January 1923 guessed | |
| EXPANSION LEAKS RECORDED IF ONE PLUG ONLY IS USED O.2 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. I.M.E.P. 138 Lbs/□" B.M.E.P. 112·0 Max. Expln. Pr.{Percy H. Rose} 465" Av. Expln. Pr.{Percy H. Rose} Mechanical Efficiency 81% Indicated Vol. Efficiency 98% FULL LINE 1" = 91·5 LBS/□" DOTTED LINE EC IO IGNITION I.C.EO ATMOS. LINE PISTON DISPLACEMENT FOR CRANK ANGLES. | ||