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).
Performance test results for Magneto No 98034 and No 98033.
| Identifier | ExFiles\Box 43\4\ Scan154 | |
| Date | 28th February 1929 | |
| X. 4021. Rolls Royce 28 Feb 29 Magneto No 98034 5.5 m/m dist gaps. 6 ft. braided cables F.A. | 100 RPM. 15°R | 150 " 25°R | 270 " 30°R | 360 " Magneto No 98033 F.A. | 100 RPM. 15°R | 140 " 25°R | 300 " 30°R | 490 " Magnetos delivered by Mr. Ward on the 1 Mar 29. A.W.A. | ||