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 system tests, comparing gap length, cable length, and sparking results.
| Identifier | ExFiles\Box 52\3\ Scan355 | |
| Date | 4th April 1920 | |
| Contd. -2- EFC {E. Fowler Clarke - Electrical Engineer} 2/T14.4.20. to some intermittent internal [handwritten: discharge] passage, or perhaps due to the coil not being properly dry after impregnation. The conditions in the present case are much more comparative and much more representative of standard conditions. It will be [handwritten: seen] that there is not much to choose between the variation of gap length with cable length for the two ignitions. When using the longer cable lengths, it was somewhat difficult to obtain a definite figure for the maximum gap which would just allow of even sparking. The results given are the mean of several readings. The maximum gaps for even sparking when the shorter lengths of cable were used were fairly definite. For the tests a single platinum point gap was used with an insulated third point, connected to the coil through the cable only (no distributor): The polarity used was such as to give the better results on the bench. EFC. {E. Fowler Clarke - Electrical Engineer} | ||