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).
Specification sheet detailing components and modifications for Wraith II and Wraith III units.
| Identifier | ExFiles\Box 155\2\ scan0154 | |
| Date | 23th September 1937 | |
| 3. Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell}1/WH.23.9.37. Wraith II. No.1. (Spare Unit) Unit as designed. W/M.{Mr Moon / Mr Moore} main bearings and steel shims. Hall's metal big ends. Up-to-date bushing of oil pump. Sludge trap, improved suction strainer and ribbed lower half. External oil pressure filter. 10" B. & B. clutch. Wraith II. No.2. Unit (25.G.VI.) As No.1 unit but with - W/M main bearings with RR.56. solid shims. Hall's metal big ends with RR.56 shims. Swedish wire valve springs. - 1 - 6 Rm.{William Robotham - Chief Engineer}260 made by Tempered Spring Co. 7 - 12 EB.3256 coiled by R.R. 2 inlet can camshaft ex C.15 unit Ex.24268. Wraith III. No.1. Unit (26.G.VI) W/Mt. main bearings RR.56. liners. (No.4.7 new after 7000 miles) Crankshaft with 2 - .125" holes in pins. A.C.G. big ends single hole feed in bush (top half) Ex.28171) Unhardened engine gears in V.{VIENNA} &NX. Bottom tappets in I/C (R.R.) Chevrolet type Ex.27960. with push rods to suit. Tappet guides tilted by boring 45'. Annulus in front and rear bush of spring drive to improve lubrication of 'cotton ducks'. K.E.965 steel. exh. valves 1.4 dia. Improved core cyl. head LeU.5684 S.65 Inlet valves 1.6 dia. New after 7000 miles. Nos. 1 - 6 valve springs S/W. (RS.{Sir Henry Royce's Secretary}540) blue. Nos. 7 - 12 " " (Swedish wire) (red and blue increased heat treat) RR.coiled. Rs.{Sir Henry Royce's Secretary}540. Rm.{William Robotham - Chief Engineer}400 top spring washers. Relief valve springs E.83790 main. Ex.28174 rocker. Lower rated spring drive friction springs. Ex.28234 springs. Rm.{William Robotham - Chief Engineer}402 caps. Set at 15 - 17 lbs. at 17 1/2" rad. Lucas suction ignition control. | ||