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).
Test and modification notes for Wraith III engine units, including special parts.
| Identifier | ExFiles\Box 155\2\ scan0211 | |
| Date | 27th April 1938 | |
| -2- Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell}2/MH.{M. Huckerby}27.4.38. WRAITH III No. 1 UNIT - Cont'd.{John DeLooze - Company Secretary} Compared with its previous condition on which diagrams were checked the flywheel inertia has been reduced by 50% to raise the major period. Further tests pending the results obtained. W.III. NO.5 UNIT. (b Bed.) Unit which has been modified for fitting in 28.G.VI. (a) Flat bottom tappets vertical with front face of cam on ℄ of tappets. (b) Latest Attwater's camwheel and spring driven R.R. distributor. Following running in take - (a) Power curve open exhaust and with silencer also advance line with T.D.C. setting. (b) 1 hr. oil consumption. (c) Valve bounce speed with silencer fitted (std.) also ensure distributor contact breaker is not flinging below this speed. (d) Unit to be tuned up generally, leaks, noises, slow running and settings etc. (e) Note whether any leak from rear end bearings. (f) Whether timing gears are O.K. for rattle and whine. (g) Observe detonations on Red Line, Shell and Ethyl up to 1500 R.P.M. (h) List of complaints for shop attention, also report on troubles experienced including R.R. governor. W.III. NO.4. Following No.5 this unit will be ready for endurance special parts including - Monikrom Camshaft (Mid. Cyl. Co.) Chrome Cylinder block (R.R.) 3 inlet valves in 7.5% chrome as forged almost to size by the Belgrave Eng. Co. | ||