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).
List of recommendations concerning the Wraith crank.
| Identifier | ExFiles\Box 8\5\ 05-page02 | |
| Date | 14th December 1936 | |
| J 1044 617 CRANK. - WRAITH Typed 14.12.36. RECOMMENDATIONS MADE TO E.{Mr Elliott - Chief Engineer} re WRAITH CRANK. 1. 2 1/2 journals 1/4" wider. 2. 1/16" off webs. 3. 1/8 off pins in length compared with standard crank. Reduce radius slightly to .093. No bearing flanges on sides of rod. Macks keyed shim. 4. Single bolter rear main bearing as long as possible without moving gear lever. 5. Moved dynamo. 6. Wraith cheapened feature. 7. New 4 port cylinder head. 8. Latest sludge trap bottom half. Rm.{William Robotham - Chief Engineer} | ||