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 plotting torsional vibration test results from a B.80 No. 2 engine camshaft.
| Identifier | ExFiles\Box 124\1\ scan0231 | |
| Date | 29th June 1939 | |
| TORSIONAL VIBRATION TESTS ON B.80 NO. 2 TORSIOGRAMS TAKEN FROM CAMSHAFT B.80 DAMPER WITH LARGE INERTIA (.0485 SLUG FT²) SET AT 318 LBS. FT. DEGREES. NORMAL BACKLASH .020 BACKLASH FIG. 4 VIBRATION AMPLITUDE DEGREES ENGINE R.P.M. RM{William Robotham - Chief Engineer}/JRS. 29-6-39 | ||