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).
Requested alterations and observed issues on the Wraith III units.
| Identifier | ExFiles\Box 6\6\ 06-page383 | |
| Date | 25th November 1937 | |
| To By.{R.W. Bailey - Chief Engineer} from Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} c. By/Cs. c. De/Mus. Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell}4/MH.{M. Huckerby}25.11.37. WRAITH III UNITS. Further to our memo on detail alteration to Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell}7/AP.19.11.37 in connection with the above unit will you please look into the following and include any alterations made on the 6 units which R.H.C. is building. (1) Valve timing markings on the flywheel are very difficult to see from the present position of the inspection cover. (2) A lug is provided at each end of the cylinder block base through which studs pass from the crankcase with nuts to clamp the block and case together. This provision is for removal of the cylinder head in the case of the high mounting. The studs appear hard on the ends of the lugs when the engine is hot and central when the engine is cold, as observed with the nuts off, due to the differential expansion between the A/C case and the I/C block. These should be given more clearance to allow expansion and consideration whether shouldered studs be used to prevent nuts locking down and allow free expansion. (3) With the coarse pitch timing gears as in the case of Ph.III, one tooth alteration makes a difference of 12° to the timing on the flywheel. An extra keyway at (18)° or 177½° to the existing would permit a finer adjustment of the timing and make it possible to get the timing within 3° of the correct marking. (4) The bottom tappets in several instances still pull out of their guides when the pushrods are removed, despite the fact that we have suction release holes in the bottom housing of the push rods. It appears that we ought to include bracket stops on the tappet cover doors in order to prevent the tappets lifting out as discussed some time ago. Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} | ||