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 failures, referencing specific reports and suggesting design changes and further experiments.
| Identifier | ExFiles\Box 69\1\ scan0086 | |
| Date | 8th May 1928 | |
| BY.{R.W. Bailey - Chief Engineer} from EFC. c. BY/RD c. Mr. Brock. X8710 EFC4/T18.5.28. IGNITION COILS. X4079 Please find attached copy of my assistant's report WC.107 which is self-explanatory, but we might add a remark to the effect that the primary winding was found to be in quite good condition, i.e. not charred in the least degree. Please also find attached copy of my assistant's report WC.108 regarding tracking along the inside of the bakelite case from the H.T. end of the secondary to the core, as indicated in diagram. It should be stated that this coil broke down when running on an open circuited distributor, varnished on inside for the purpose of a test, of that distributor, but we have had a case where a similar breakdown occurred in normal circumstances. We are making an experiment with a coil case varnished on the inside. We suggest that some means should be considered of covering up the bare metal spring connection, as in any case there is a tendency for this to corrode. It might, for instance, be possible to wrap this round with light rubber tape, if this could be considered a production job. This would probably help to reduce brushing from this spring connector which brushing probably itself contributes to the generation of acidic moisture. This type of failure strengthens the argument for experimenting on the type of coil with central H.T. In this connection we also attach a copy of my assistant's report WC.60 dealing with the advantages of this type of construction, though in the case of point No.3, we shall be giving the matter further consideration as to whether the omission of the ballast resistance is feasible. EFC. WC.60. WC.107/8 attached. | ||