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).
Crankshaft hardness, comparing with other manufacturers and investigating scoring issues.
| Identifier | ExFiles\Box 114\3\ scan0145 | |
| Date | 9th September 1937 guessed | |
| -2- We have previously reported that in our opinion our crankshafts are on the soft side, and from remarks of Allen of the Paris Depot who has stated that their rehardened crankshafts are definately harder than ours, goes to prove the issue. They have the utmost difficulty in drilling after a re-hardening, and now take the precaution to drill before the rehardening. Bentleys had serious trouble with their cranks for the valve gear drive, until they made them glass hard, due to the connecting rod being made of Duralumin. Halls' metal is of a similar nature, which requires a hard surface, otherwise it will score and wear. It is quite possible that a lot of our trouble with crank journals scoring is due to inconsistent hardness of the cranks, and we believe it is serious enough to have a thorough investigation. Rm{William Robotham - Chief Engineer}/GWH.{George W. Hancock - Head Chateauroux} | ||