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).
Ignition coil performance, comparing a Lucas coil with a ballast to other competitor models and noting its inferiority when hot.
| Identifier | ExFiles\Box 164\5\ img103 | |
| Date | 23th November 1931 | |
| -2- Hs{Lord Ernest Hives - Chair}/Wst.1/AD23.11.31 contd. of the spark segments prevents to a large extent burning of the surface due to local heating. We think this distributor would cause much more trouble due to contact points than our own but would last longer as regards life. We are sending to W.W. the two sets of contacts used on these tests for R's inspection. Ignition Coil. This did not give such a good electrical performance as our own new coil now being tested on 18-GIV. The coil when placed under a heating test almost "petered" out at temperatures under which our own coil would still function O.K. For instance the maximum steady voltage measured on the coil secondary when cold was approx. 8000 volts but after 2 hours running on a fully charged battery in an atmosphere at 80ºC. the volts dropped to 6000. The sparking performance at low battery voltages was also inferior to ours. Although this Lucas coil is of the outside primary type Messrs Lucas have fitted a ballast on to the end of the coil inside the case, and this locally heats the coil tremendously and we largely attribute this to be the cause of its bad performance hot. The idea is probably to use the same coil without a ballast for 6 volt systems. In any case fitting the ballast on to the coil is definitely bad. We have also proved on road tests that this type of Lucas coil is much inferior to either Delco-Remy, Marelli, De Jon or our own. Hs{Lord Ernest Hives - Chair}/Wst. | ||