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).
Table of magneto distributor dimensions, make ratios, and ranges expressed in practical values.
| Identifier | ExFiles\Box 4\5\ 05-page221 | |
| Date | 24th June 1921 | |
| X.430. TABLE OF MAGNETO DISTRIBUTOR DIMENSIONS, MAKE RATIOS, AND RANGES EXPRESSED IN PRACTICAL VALUES OF THE DISTRIBUTOR PITCH IN EACH CASE. X.800. | Magneto. | Type. | Width of carbon brush. | Width of seg: | Sum of brush & seg. | Make ratio. | Sum of make ratio Brush & Segment. | Range. | Forward overlap at advance. | Forward overlap at retard. | Backward overlap at advance. | Backward overlap at retard. | Remark | |---|---|---|---|---|---|---|---|---|---|---|---|---| | U.S.A. Bosch | ZR.6 Ed{J. L. Edwards}19 | .22 | .61 | .83 | .85 / 1.68 | 1.68 | .21 | .13 | .34 | .55 | .34 | Same as Ed{J. L. Edwards}18 but differently wound armature | | Watford | ED{J. L. Edwards}6c | .15 | .64 | .79 | .88 | 1.67 | .18 | .19 | .40 | .48 | .30 | | | Watford | ELO.6 | .14 | .68 | .82 | .98 | 1.70 | .34 | .125 | .46 | .575 | .235 | | | ||