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).
Faults with the Watford magneto and the adoption of a new sleeve-type magneto.
| Identifier | ExFiles\Box 4\5\ 05-page200 | |
| Date | 10th August 1921 | |
| A 130 3 To C.E. From R.{Sir Henry Royce} Copy to Mr. W. G.{Mr Griffiths - Chief Accountant / Mr Gnapp} S. R.{Sir Henry Royce} B. C. Acknowledged. Rolls-Royce of America Inc. (For the attention of Mr. V.{VIENNA}) RS{Sir Henry Royce's Secretary}/G10/8/21. K4801 RE MAGNETOS. X5375 X4183 Regarding magnetos, the only fault we have been able to so far find with the Watford is that the safety spark is rather short, which seems to be always the case on the smaller sizes of magnets of all makes. In certain conditions of compression in the cylinders and wide spark gaps at the ignition plugs, this causes the safety spark gap to act instead of the spark passing at the plug points, and so misfiring occurs. On the European cars we are adopting the sleeve type of Watford in which the collecting ring from the armature can be larger by the thickness of the sleeve. This magneto, although of light and small size, has all the advantages of the bigger model, firing at equal and low speeds in any position of the advance, and so permitting the full retarding of the magneto ignition when running dead slow. H.{Arthur M. Hanbury - Head Complaints} RECEIVED JUN 15 1921 | ||