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 chart showing piston displacement for crank angles of a Hispano engine.
| Identifier | ExFiles\Box 22\1\ Scan138 | |
| Date | 4th August 1917 | |
| EXHAUST LEAKS RECORDED IF ONE PLUG ONLY IS USED 02 Spring Used—Rating 91.5 Diagram Area 12.05□" Engine HISPANO Cyl. No. 6 Air Temp. 12°C Bar Temp. 765mm Cooling Water Temp. 80°C R.P.M. 1500 Lbs. Lift 137 H.P. 80 I.M.E.P. 138 LBS □" B.M.E.P 112.0 LBS/□" Max. Expln. Pr.{Percy H. Rose} 465" Av. Expln. Pr.{Percy H. Rose} 448 Mechanical Efficiency 81% Indicated Vol. Efficiency 98% FULL LINE DOTTED LINE 1" = 91.5 LBS/□" 0.2" = 18.3 " " EC IO ATMOS LINE Ignition I.C.E.O. PISTON DISPLACEMENT FOR CRANK ANGLES. HISPANO - 4.8.17. | ||