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 detailing the results of preliminary tests on two type EW6 sleeveless magnetos.
| Identifier | ExFiles\Box 65\3\ scan0100 | |
| Date | 10th September 1927 | |
| EFCl/T. 10th September 1927. Messrs. North & Sons, Ltd., Whippendell Road, Watford. Dear Sirs, For the attention of Mr. R.E.North. Further to our letter ref. EFC4/T. of the 8th inst., we are writing you further as promised concerning the preliminary tests on cars of the two type EW6. sleeveless magnetos, Nos. 99171 and 99802. The former of these, No. 99171 has been put on one of our experimental cars. It is agreed by the testers that the electrical functioning is particularly good. They have however, given us one very definite complaint from this machine (which we have confirmed) namely of noisy contact breaker. I fear this is easily too bad to enable this machine to pass our production critics. We understand this noise was there from the first. On further enquiry, we find there is a complaint of slight gear noise developing when the magneto gets hot. A copy of our tester's report concerning this magneto is attached. With regard to the second magneto No. 99802, this was submitted to our Test Dept. to see if they were favourably impressed with it from a production point of view. On first running the machine they were very favourably impressed, but latterly the magneto developed a very pronounced knocking noise in the course of a run of about 40 miles. We have ourselves heard this and it sounds very much like armature fouling. Its periodicity is definitely that of the rotation of the magneto. At first it was thought it might be something to do with gears but latterly it was concluded that the symptoms were such that it could not be so. We are this morning running the machine on our bench in order to confirm this point, and then we propose to despatch it to you straight away for correction. We hope it will leave our Works this morning. | ||