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).
Laboratory tests comparing French and British sourced enamelled copper wire for ignition coils.
| Identifier | ExFiles\Box 164\5\ img046 | |
| Date | 1st February 1931 | |
| X6058. To By.{R.W. Bailey - Chief Engineer} from EFC. c. Sft{Mr Swift}/Mr.Brock. EFC10/ADL1.2.31. X.6058. IGNITION COIL SECONDARY ENAMELLED COPPER WIRE. Further to our EFC2/ADL7.9.30 two further samples of wire, one from a French firm (as used by Messrs. Lucas) and the other an improved grade of wire submitted by Messrs. Connolly, have been subjected to tests 4 and 5 of the specification of laboratory test we sent to you under cover of our EFC2/ADL7.9.30 and the following is a copy of my assistant's report WE.73 in which the results of these tests are stated :- "On test 4. both samples were O.K. no appreciable effect being observed. On test 5. the average breakdown volts taken from three tests of each grade of wire gave the following results :- French wire 354 volts. Connolly's wire 334 volts. It will be seen that the Connolly's sample is no better than the previous sample tested which gave a breakdown figure of 332 volts but as was stated in that report providing consistency of wire diameter can be obtained, we consider Connolly's to be a sound grade of wire. The French wire is apparently a better wire but not quite as good as Swiss and Dudlo electrically." It would appear from the above that we are still justified in considering Messrs. Connolly's wire to be the best obtainable from a British source. EFC. | ||