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, maintenance, and costs of ignition system components like rockers, contact breakers, and distributors.
| Identifier | ExFiles\Box 61b\4\ scan0052 | |
| Date | 18th July 1921 guessed | |
| Oyl - G 16721 Sheet #4. We left the oil in to note whether it had any effect on the ignition, but detected none. Up till the time of the accident there was no oil in the case. A drop of light oil was put on the rocker pivot at the start and a small spot of grease was put on the rubbing contact of the rocker with the end of a match. This is all the attention the rocker is supposed to receive, and is said to be enough for the life of the rocker. The rocker is said to run thirty or forty thousand miles. During this time it may be necessary to adjust the tungsten contacts four or five times, smoothing down the rough spots with a stone or fine file and re-adjusting. The rocker is removed by removing the spring ring on the pivot and loosening the L.T. terminal which releases the spring and connecting strip. A new rocker costs $.40, and an entire new contact breaker assembly in cup ready to drop in place in the housing costs $2.60 (with tungsten points). The mileage claimed for the rocker points is borne out by my own experience with a far cheaper ignition outfit on the Overland. In this case the whole of the contact breaker unit is supposed to be thrown away after the tungsten points go bad, which is supposed to be after 25,000 miles or so. A new contact breaker unit costs about two dollars. Actually after about 16,000 miles I found the points sticking and managed to get the rocker out and grind up its contact roughly. The other contact could not be reached, but grinding the one point proved sufficient and the ignition has been perfect since then. The points on 4-EX as it left the United States had run about 3500 miles. X800(s) X3309 Distributor - The distributor electrodes are platinum, fitted at our request by the American Bosch Co. The trailing point on the rotor was also fitted by Bosch at our request. With regard to the distributor cap being "blind", this is so on all American systems without a single exception that I know of. The brass inserts which are normally used for the six jump electrodes in the cap, are tooled out true with the spigot, after molding, and this is relied on to in-sure concentricity of the rotor and cap. | ||