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 for conical valve springs fitted to chassis 58NA.
| Identifier | ExFiles\Box 80\3\ scan0192 | |
| Date | 26th May 1914 | |
| X290 FITTED TO CHASSIS 58NA{Mr Nadin} ON 26. 5. 14. X. 565. CONICAL VALVE SPRINGS. These springs are made to drawing E4247 and have a less number of coils than the conical springs previously tested, viz., E3820. 6 spares are sent with the car they are fitted with the top washers E3361 and bottom washers E2659. | ||