Three graphs comparing the BMEP vs RPM of 'Japan I' and 'Peregrine' engines, with and without detonation, using Shell Mex fuel.
| Identifier | ExFiles\Box 42\4\ Scan069 | |
| Date | 20th August 1919 guessed | |
| CURVES SHEWING THAT J1 CAN GIVE MORE SPECIFIC OUTPUT WITHOUT DETONATION THAN PER ALL TESTS SHELL MEX FUEL GRAPH A: COMPARISON OF USEFUL B.M.E.P THAT CAN BE OBTAINED ON THE ROAD JAPAN(Experimental Engine) I COMPARED WITH PEREGRINE(Experimental Bentley car never produced / Aero Engine) Y-AXIS: B.M.E.P. X-AXIS: R.P.M. CURVE LABELS: ① JAPAN(Experimental Engine) I, ② PEREGRINE(Experimental Bentley car never produced / Aero Engine) GRAPH B: JAPAN(Experimental Engine) I Y-AXIS: B.M.E.P. X-AXIS: R.P.M. KEY: ① MAXIMUM B.M.E.P. WITH FULL IGNITION ADVANCE ② USEFUL B.M.E.P. WITH IGNITION RETARDED TO ELIMINATE DETONATION GRAPH C: PEREGRINE(Experimental Bentley car never produced / Aero Engine) Y-AXIS: B.M.E.P. X-AXIS: R.P.M. X-AXIS SUB-LABEL: 25 M.P.H. KEY: ① MAXIMUM B.M.E.P. WITH FULL IGNITION ADVANCE ② USEFUL B.M.E.P. IGNITION RETARDED TO ELIMINATE DETONATION | ||
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).