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).
New procedure for boring the Wraith crankcase to incline the bottom tappets.
| Identifier | ExFiles\Box 132\3\ scan0071 | |
| Date | 10th August 1937 | |
| Ey. from Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} c. Ey/CS. 616 SECRET. Rm{William Robotham - Chief Engineer}/Swdl{Len H. Swindell}1/R.10.8.37. WRAITH CRANKCASE. In order to obtain correct rotational movement of the Wraith bottom tappets to avoid tearing up of the surface, it has been found necessary to give them an inclination of 45'. Up to the present this has been carried out experimentally by boring each guide bore to the above angle individually. This necessitates pegging of the guides in the crankcase bores in the correct position to prevent any possibility of turning. From a production point of view, this is not so satisfactory as the following which should be included with the latest modified crankcase drawings and instructions. When boring the crankcase for the tappet guides, the rear end of the crankcase should be lifted so that the crankcase is now at an angle of 45', the boring and counter boring machine for the bore and the flange of the guides being brought down vertically. The guides are then pressed in, in the normal manner without having to locate, and the top face of the guide flange machined to the crankcase top face. Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} | ||