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).
Urgent test requirements for the Wraith III No.4 and B.V. No.6 engine units.
| Identifier | ExFiles\Box 155\2\ scan0306 | |
| Date | 27th March 1939 | |
| -2- Wraith III No.4. Before carrying out the programme as instructed in the previous memo, the following tests are urgently required. (1) Power with existing straight through drive gearbox, i.e. no gears. (2) Power with Wraith box loaned from the shop, which is complete with gears and filled with Castrol XL to the normal level. (3) Ensure that unit has modified cored cylinder block and head (EW.1922/3), which according to the specification it has. Check water temperature along the cylinder head with a normal car radiator (not the normal header tank), also check valve temperatures. B.V. No.6 Unit. Irrespective of whether tests on Wraith III No.4 are completed or not, this unit should be fitted on the bed when ready for endurance. Conditions of endurance should be precisely the same as carried out on B.III No.5 unit (June 1938), the object being to compare the latest Vandervell 3-layer bearings on B.V. No.6 unit with the normal Vandervell W/M bearings run on B.III No.5. Other special features in B.V. No.6 are:- (a) Monichrome camshaft running direct in crankcase. (b) Atwater camwheel and Metalastik coupling. (Check for rattle both light and under load before starting the endurance. (c) 3-Layer Vandervell main bearings. | ||