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).
Three performance indicator diagrams for a 90/90 Lb 2' stroke low-pressure system under various conditions and RPMs.
| Identifier | ExFiles\Box 105\3\ scan0298 | |
| Date | 11th November 1935 guessed | |
| Graph 1: 90/90 LB 2" STROKE. LOW PRESS. COLD-25°C. ONE ATMOSPHERIC INLET TO "HAT". .250" HAT .005" CLEARANCE R.P.M. 360 260 180 90 Y-Axis: 308 LB/□" X-Axis: 120' I.S. Graph No: 7 Graph 2: 90/90 LB 2" STROKE LOW PRESS 60°C. ONE ATMOSPHERIC INLET TO "HAT" R.P.M. 360 260 180 90 Y-Axis: 308 LBS/□" Graph No: 8 Graph 3: 90/90 LB. 2" STROKE. LOW PRESS. AFTER RE-COOLING. ONE ATMOSPHERIC INLET TO "HAT". B.P. LOAD. 140 LB. DROPPING TO 110 LB. R.P.M. 360 260 180 90 Y-Axis: 308 LB/□" Graph No: 9 | ||