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).
The alteration of the taper screw plug for crankshaft oil holes on Bentley 60 and 80 models.
| Identifier | ExFiles\Box 123\5\ scan0138 | |
| Date | 28th October 1938 | |
| BY/NS.{Norman Scott} c. Rm.{William Robotham - Chief Engineer} c. HPS.{Horace Percy Smith - Experimental Factory Mgr} Rules 1044 DA.{Bernard Day - Chassis Design}9/G.28.10.38. BENTLEY 60. CRANKSHAFT. SWPL Please receive herewith :- E.CD.929 Plug for Crankshaft Oil Holes - Bentley 60. Owing to the difficulty of obtaining taps, dies and gauges for the special taper screw plug called for on the Bentley 60 Crankshaft E.CD.412, we have altered the tapered screw plug to Brigg's .125" taper gas thread which is a standard size of thread, and for which tools can more easily be obtained. It is necessary to increase the counterbore at mouth of screwed hole to .500" diameter to allow room for peening the metal over to look and seal the plug. Care should be taken when tapping, to avoid damage to the conical seatings inside crankpins. The taper screwed plug is the same as used on the Phantom lll Forked Connecting Rod. Now that the "Welch" type plugs have been abandoned for the Bentley 80 crankshaft this alteration of the screwed plug should also be applied to the Bentley 80 crankshaft. Will you please make the necessary alterations to the detail drawings to agree with this change. DA.{Bernard Day - Chassis Design} | ||