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).
Letter to Messrs. North & Sons regarding the performance of type LW6A magnetos.
| Identifier | ExFiles\Box 65\3\ scan0389 | |
| Date | 22th July 1929 | |
| X7791 C. By C. Roy{Sir Henry Royce} C. Mailing EFC2/AD. 22nd July, 1929. Messrs. North & Sons, Whipperndell Rd., WATFORD. Dear Sirs, We are so far very pleased with the bench and chassis performance of the six type LW6A magnetos with which you have recently provided us for experimental purposes. Particularly we are pleased to note the improvement in the short circuit primary winding ampere speed curve, expressed in the percentage manner in the way we have described to you, this resulting, as it does, in a much better low speed performance for the same maximum energy of spark. With one slight exception all the magnetos are to date doing very well, two on bench test and four on experimental chassis, special as well as general tests haveing been made on chassis to satisfy ourselves on this point. Some time ago, at the time we pointed out to your Mr. Allen the importance, as it appeared to us, of getting a good total cross sectional conductance on the primary winding, we gave (or shewed) to you we think, a set of curves in which this feature was comparatively indicated for various machines including the present standard LW6 and the R.Bosch. Now we are pleased to enclose a similar set of three curves only, one being for the LW6A magneto, one for the present standard LW6 and one for the R.Bosch magneto above mentioned. You will agree that a comparison of these curves is highly instructive in view of the considerably better low speed performance which we have realised on these new LW6A magnetos. Yours faithfully, FOR ROLLS-ROYCE LIMITED. Set of curves enclosed. | ||