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).
Report page comparing the specifications and test results of various Bosch and Watford magnetos.
| Identifier | ExFiles\Box 49\5\ Scan171 | |
| Date | 31th July 1922 | |
| Contd. -2- EFC {E. Fowler Clarke - Electrical Engineer} 1/T31.7.22. (1) (The first magneto/referred to is the latest one from U.S.A. incorporating the latest modification to the armature and which we believe is representative of the standard magneto at present used on the U.S.A. R.R. cars. This distinguishes the results of tests from those given under cover of our EFC {E. Fowler Clarke - Electrical Engineer} 4/T3.2.21 for the U.S.A. Bosch ZR.6 No.2998784). The following are results of experimental tests, given in a similar manner to that adopted in our report EFC {E. Fowler Clarke - Electrical Engineer} 4/T3.9.21, on three Bosch magnetos, (e.g. R.Bosch ZR.6, U.S.A. Bosch ZR.6, and U.S.A. Bosch B6), the only difference being an improvement in the method of taking the slow speed sparking characteristics by which the magneto was driven positively in these tests by means of a chain from a motor with a massive flywheel, so that the objection of the loss of angular velocity on the pull-over when the belt is used, does not now hold:- (1) The weight of the U.S.A. Bosch ZR.6 magneto is 15.4 lbs. The weight of the Watford EO6c magneto is 12.8 lbs. The weight of the Watford ELO6 magneto is 17.7 lbs. (2) The ZR.6 ED. {J. L. Edwards} 19 magneto is, in mechanical design, identical with the previous ZR.6 ED. {J. L. Edwards} 18 (See our report EFC {E. Fowler Clarke - Electrical Engineer} 4/T3221), but has a differently wound armature to that machine, viz. a BB instead of an NB armature. The EO6 c Watford differs from previous EO6 magnetos, in addition to the ways mentioned above, in that it has a system of two springs bearing on the contact breaker cover | ||