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).
Technical report on special ignition coils, presenting gap-speed curves and comparing performance.
| Identifier | WestWitteringFiles\D\May1920\ Scan72 | |
| Date | 22th May 1920 | |
| R.R.235A (100 T) (S G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 643, 19-2-20) G 2618 To R.{Sir Henry Royce} from EFC. c. CJ. c. Bn.{W.O. Bentley / Mr Barrington} c. Da.{Bernard Day - Chassis Design} c. EP.{G. Eric Platford - Chief Quality Engineer} c. HS.{Lord Ernest Hives - Chair} c. E.{Mr Elliott - Chief Engineer} ORIGINAL EFC1/T22.5.20. X.3775 - SPECIAL IGNITION COILS. Further to our EFC2/T13.4.20, we now present maximum gap-speed curves for coils Nos. E.12 and E.16 previously described in the above mentioned report, thus completing the bench investigations of these special curves. These curves may of course be directly compared with the curves issued under cover of that report. With regard to coil E16, it will be seen that the performance is not quite as good as coil E.12 previously reported, in spite of the fact that the number of secondary turns is the same and the diameter of the secondary wire greater, the insulation, however, not being as good. With regard to coil E.16, it will also be seen that the performance of this is not quite as good as that of E.14 previously reported in spite of the increased number of turns, the diameter of the wire in this instance being less. It will, however, be remembered that coil E.16 was made sometime ago and the improvement in the manufacture of coils of late may therefore account for this difference. It is not considered that the number of secondary turns should be less than 18,000 in order to allow a reasonable factor of safety for adverse conditions of ignition plugs. Any advantage due to intensified secondary winding is not apparent on the bench. EFC. | ||