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).
Specifications and exceptions for various Wraith III and Bentley III engine units.
| Identifier | ExFiles\Box 155\2\ scan0201 | |
| Date | 7th February 1938 | |
| -5- Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell}1/MH.{M. Huckerby}7.2.38. Wraith III No.8 (Test Bed unit). Latest unit as No. 7 with the following exceptions. Pistons with high pressure scraper and compression rings L section 2nd. ring. Original normal section big ends. AC.6 with keyed shims. No end thrust plunger on camshaft. Wraith III No.9 (29.G.VI). Latest unit as No.7 with following exceptions – Thin section big end bearings (.002 no shims) with flanges. B.III No.1 Unit (Test bed). As latest Wraith but with – Big end bearings thin section without shims, with flanges. Std. Wraith head but with .010 gasket (Klinger) making compression ratio 6.2 : 1. Extra 3° offset keyway in cam centre B.III camshaft EB.5400. 2 S.U. carbs. on designed pipe (controls mockedup). Aerolite pistons. B.III No.2 (1st. Bentley III chassis). As No.1 unit except – Main bearings but faced adapted by using shims behind bearings. Original normal section big ends AC.6 with keyed shims. End thrust plunger on camshaft, balancers retained. Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} | ||