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).
Two graphs comparing unbalanced and crankshaft balanced loads on a Kestrel engine's end main bearing at different power and speed settings.
| Identifier | ExFiles\Box 138\1\ scan0014 | |
| Date | 24th February 1932 guessed | |
| HS{Lord Ernest Hives - Chair} 539 KESTREL END MAIN BEARING LOAD Top Graph: 500 HP AT 2250 RPM LEGEND: ____ UNBALANCED -- -- CRANKSHAFT BALANCED SHADED AREA 18.0 SQ" Bottom Graph: 555 HP AT 2500 R.P.M. SHADED AREA 20.0 SQ" Axes and Labels: Y-AXIS: LOAD in lbs (0, 1000, 2000, 3000, 4000) X-AXIS: CRANK ANGLE (0, 100, 200, 300, 400, 500, 600, 700) NOTE BETWEEN GRAPHS: 0° CRANK ANGLE PLAIN RD TDC | ||