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).
10,000 mile bench ignition contact point experiments.
| Identifier | ExFiles\Box 35\6\ scan 277 | |
| Date | 19th May 1927 | |
| -2- 10,000 MILE BENCH IGNITION CONTACT POINT EXPERIMENTS. | Conditions | Contact point material ||| |---|---|---|---| | | **Iridio-platinum (pt.)** | **Tungsten (British) (Tn.B.)** | **Tungsten (U.S.A.) (Tn.U.)** | | | Remarks. | Remarks. | Remarks. | | **Previous std. coil; otherwise std. Points offset from cam by using long rubbing block.** | Finished 11.12.26. Pip filed off after 7000 miles. Condition good. Surface clean and white. 10P | Finished 16.10.26. Lever pt.good, screw oxidized slightly. Fairly even contact. Sharp point filed off after 7000 mls. 10T | | | **Previous std. coil; otherwise std. Increased spring pressure on points.** | Finished 25.4.27. Condition good, not trimmed at all. Misfiring just commenced at 10,000 miles. 13P | Finished 25.4.27. Condition good, no misfiring, no trimming. Surfaces slightly oxidized. 13T | Load on points 1 lb.7 ozs. | | **Previous std. coil. Std. ballast. Double value condenser.** | | Finished 20.11.26. Condition poor. Pips form rapidly causing misfiring. 14T | | | **Previous std. coil; otherwise standard. Periodic reversal of current, every 24 hours.** | Finished 19.1.27. Condition good, absence of pip and cavity, and small wear. 15P | Finished 19.1.27. Condition V.fair. Hardly any wear and absence of pip or cavity, but surfaces slightly oxidised. 15T | | | ||