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).
Scheme for mass-producing a cheap, drop-forged 4-cylinder crankshaft for the Silver Ripple model.
| Identifier | ExFiles\Box 118\1\ scan0375 | |
| Date | 4th January 1944 | |
| CONFIDENTIAL 102 To. Wym.{G. Harold Whyman - Experimental Manager} from Jnr.{Charles L. Jenner} Jnr.{Charles L. Jenner}9/GAB.4.1.44. c. to. Rm.{William Robotham - Chief Engineer} Ev{Ivan Evernden - coachwork}/JD.{J. Draper - Frames} PSN (Glasgow) Bv. Ev{Ivan Evernden - coachwork}/HH. Silver Ripple PL.2875, Drop Forged 4 Cylinder Crankshaft. Reason for scheme: To make a cheap shaft having black edges to the slabs and balance weights just as it comes from the forging dies. This being the only way to consider production of large quantities. Description of the scheme: The pins and the journals are left solid to save boring time and the expense of fitting plugs in the holes. There are two unknowns about having a solid shaft, it makes us depart from our well tried and satisfactory method of oil ways and the increased inertia of the pins may impose too heavy aload on the main journals bearings. The actual forging is shewn with a minimum machining allowance of .100 with 7° draw everywhere. Instructions: Ev{Ivan Evernden - coachwork}/HH please to detail. Remarks: To justify the die cost it will be understood that this only need be considered for mass production quantities. We can please ourselves whether we bore the shaft out or not of course. Jnr.{Charles L. Jenner} Prints: Wym.{G. Harold Whyman - Experimental Manager} Ev{Ivan Evernden - coachwork}/JD.{J. Draper - Frames} Ev{Ivan Evernden - coachwork}/HH. Pan (Glasgow) Ashby. | ||