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).
Comparison of B.T.H. and Watford magnetos for the Falcon X aero engine, discussing performance tests and oil-related faults.
| Identifier | ExFiles\Box 43\4\ Scan031 | |
| Date | 13th December 1926 | |
| To R.{Sir Henry Royce} from EFC. c.c. BJ. Wor.{Arthur Wormald - General Works Manager} c. E.{Mr Elliott - Chief Engineer} Da.{Bernard Day - Chassis Design} c.c. Rg.{Mr Rowledge} By.{R.W. Bailey - Chief Engineer} Wd.{Mr Wood/Mr Whitehead} X4021 EFCl/T13.12.26. MAGNETOS FOR FALCON X. AERO ENGINE. Points of comparison between the B.T.H. SCL2-7 and the Watford type IS.12. X3832 b x4021 We now attach copy of the General Specification of Performance of Magneto for Falcon X. Engine. Copies are being sent to Watho & BTH Co. Comparative electrical performance tests of the above two types of magneto have been made, and in this connection please find attached copy of my assistant's report WB.{Mr Brazier/Mr Bell}118. In the tests on Falcon X engine, both types of magneto have suffered to some extent from platinum point gap increasing in size by burning away, due to the presence of oil. Perhaps this fault is not quite so bad on the B.T.H. as on the Watford. In both these cases the point has been taken up with the makers and the B.T.H. have pointed out to us that they have provision at each end of the magneto for stopping the passage of oil from the engine through the magneto rotor to the contact breaker. In spite of this, a certain amount of oil does get to the contact breaker, some of which may be due to overoiling the bearing. We have had cases of the gap being so far increased as to so far advance the timing of the magneto as to cause misfiring in the advanced position. In one B.T.H. case, even an increase of .004" brought this about, and the point is being taken up with the makers that we consider the timing of the magneto might be slightly re-arranged to prevent this happening in the event of the gap increasing. Contd. | ||