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).
The performance and issues with a set of 14 m/m Cormundite ignition plugs over 10,000 miles.
| Identifier | ExFiles\Box 162\5\ img041 | |
| Date | 21th August 1938 | |
| Childs Have you given E.P.a Set of short reach Plugs 600lc Rm{William Robotham - Chief Engineer}/Mr.Childs EP.{G. Eric Platford - Chief Quality Engineer}1/MH.{M. Huckerby}21.8.38 SPECIAL 14 m/m (CORMUNDITE) IGNITION PLUGS USED ON 21.G.IV. The above plugs have now been returned to you as requested. Total running 10,000 miles (actually 9,996). After first inserting these plugs no trouble was experienced until about 4,500 miles'running, when the engine commenced to misfire slightly on pick-up, also erratic slow running. This became worse, and at 5,145 miles the plugs were taken out. The gaps were found .030" (average) - originally set .018/.020". The plugs were cleaned, re-set .018/.020", and replaced. Engine ran then satisfactorily. After a further 4,500 miles' running similar trouble again commenced, and became worse, and after 4,851 miles the plugs were removed and handed to you as taken out. Now appear to be beyond further adjustment, and replaced with a further set of special plugs (Cormundite), 14 m/m K.L.G. Of the 10,000 miles' running, about 800 miles were run on Ethyl fuel. EP{G. Eric Platford - Chief Quality Engineer} | ||