The replacement of primers with a pilot jet.
| Identifier | ExFiles\Box 74\2\ scan0069 | |
| Date | 2nd February 1922 guessed | |
| X4287B. Pilot Jet to replace Primers | ||
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).