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).
Investigation report on noisy and misfiring issues in two Watford E.O.6 magnetos.
| Identifier | ExFiles\Box 70\4\ scan0230 | |
| Date | 2nd May 1927 | |
| Copy. X8797 EFC. --- WC.13. 2.5.27. ----- X.8796. Watford E.O.6. Magnetos Nos.96128 and 96130 with enclosed armature tunnels. --------------------------------------------------------- These two magnetos have been returned to the Lab. by Mx.{John H Maddocks - Chief Proving Officer} as being noisy, and misfiring at high speeds (in the case of No.96130). We have run these magnetos on our bench rig and as regards noise we do not consider them to be worse than standard machines but we accept the Test Department's statement owing to their greater experience with noise problems. The only noise perceptible is certainly a combination of sleeve and contact-breaker impulse. In the case of No.96130 we found that the safety gap was small (7.5 mm) and at high speeds, particularly at retard, discharges occurred at the safety gap in preference to the 5.5 mm. discharge gaps in air connected to the distributor. By removing the end cover this intermittent arcing at the safety gap practically ceased and the magneto would spark regularly up to 4000 r.p.m. on external 5.5 mm. gaps. H.E.W. | ||