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).
Technical memorandum detailing design specifications and changes for the Wraith III engine.
| Identifier | ExFiles\Box 6\6\ 06-page118 | |
| Date | 1st February 1937 | |
| SECRET File 600 BY.{R.W. Bailey - Chief Engineer} c. Rm.{William Robotham - Chief Engineer} HPG. E/JNR.{Charles L. Jenner}1/HP.1.2.37. re Wraith III. The above engine has three timing gears and as it is called Wraith III it will be easy to memorize the specification. We send you herewith LeC.5804 which is the main drawing, and covers the bulk of the internal design. The parts being:- Cylinder head and rocker gear. Cylinder block which has .5 longer water jackets. Cylinder skirts which are shorter in length. Crankcase. Camshaft and flat faced tappets. The width of the crankcase has been increased so that in the future we shall have room, if we wish, to fit the engine with increased diameter big-end bearings. It will be noticed that the oil gallery pipe has been deleted from its old position on account of cost. The gallery pipe is now suspended off the crankcase main bearing webs. Every effort has been made to reduce cost, and to cut out small features, also all reaming and boring diameters have been made in even 1/16ths or 1/m.m. LeC.5804 herewith. E/JNR.{Charles L. Jenner} Print to Rm.{William Robotham - Chief Engineer} | ||