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 against piston displacement for various crank angles.
| Identifier | Morton\M4.2\ img008 | |
| Date | 1st January 1923 | |
| 6.2 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. 2500 Lbs. Lift 108 H.P. I.M.E.P. 118 LBS/D" B.M.E.P 88.2 Max. Expln. Pr.{Percy H. Rose} 350 Av. Expln. Pr.{Percy H. Rose} Mechanical Efficiency 74.5% Indicated Vol. Efficiency 88% DOTTED LINE SPRING RATING 6.2 LBS/D" Graph Text: IGNITION EC TDC IO ATMOS. LINE I.C., E.O PISTON DISPLACEMENT FOR CRANK ANGLES. Side Text (Vertical): REF 6/205 / 23 FULL LINE 91.5 LBS / D" DOTTED LINE 6.2 LBS / D" | ||