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).
Comparison table for various Bensport J.1. crankshaft configurations and their properties.
| Identifier | ExFiles\Box 85\5\ scan0030 | |
| Date | 11th May 1933 guessed | |
| BENSPORT J.1. CRANKSHAFTS. | | EB.39. | 1.5 Holes in Journals. 1.350" Pins. | 1.6 Holes in Journals. 1.350" Pins. | 1.750 Holes in Journals. 1.500" Pins. | |---|---|---|---|---| | Stiffness | 52500 | 50000 | 47800 | 46000 | | Inertia | 110 | 105.5 | 105 | 101 | | Critical Speed | 1 | .995 | .98 | .98 | | Speed with additional c'wts | .98 5 | .98 | .964 | .964 | | ||