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).
Graph showing the results of a torsion test on a 20 HP crankshaft from forging to finished shaft.
| Identifier | WestWitteringFiles\R\2December1927-February1928\ Scan023 | |
| Date | 6th December 1927 | |
| FORGING DIMENSIONS: (AVERAGE) 20 HP CRANKSHAFT - TORSION TEST. FORGING TO FINISHED SHAFT. TABLE OF DIMENSIONS: A.{Mr Adams} 2.375" JOURNALS B. 1.900" CRANKPINS C. 1.100" WEB (THICK) D.{John DeLooze - Company Secretary} 1.350" TO INSIDE FLASH. E.{Mr Elliott - Chief Engineer} 1.200" OUTSIDE FLASH F.{Mr Friese} 2.550 WEB WIDTH. G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 4.625" CRANK RADIUS 2.250" GRAPH AXES: Y-AXIS: TORQUE ON NOSE - LBS. FT. X-AXIS: ANGULAR DEFLECTION - DEGREES. MANUFACTURING STAGES: ① AS FORGED. ② JOURNALS TURNED FROM 2.375 DIA TO 2.200 DIA. WEBS 1.015 THICK ③ CRANK PINS FROM 1.900 TO 1.625 DIA. WEBS .805 THICK. ④ JOURNALS REDUCED FROM 2.200 TO 2.030 DIA. ⑤ JOURNALS BORED 1.250 DIA ⑥ WEBS PROFILED FROM 2.550 WIDE (FORGED) TO 2.200 WIDE ⑦ CRANKPINS REDUCED FROM 1.625 TO 1.530 DIA. ⑧ CRANK PINS BORED .750 DIA. (FINISHED). GRAPH DATA: %AGE REDUCTION IN STIFFNESS PER OP. (1 to 2): 32.5% (2 to 3): 35% (3 to 4): 7% (4 to 5): 10.5% (5 to 6): 18% (6 to 7): 6% (7 to 8): 6% | ||