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 spark gap measurements in m/m for 6 cylinders and a coil under various speed and load conditions.
| Identifier | ExFiles\Box 83\1\ scan0126 | |
| Date | 12th June 1936 guessed | |
| MEASUREMENT OF SPARK GAP IN m/m.{Mr Moon / Mr Moore} No.1 Cyl. No.2 Cyl. No.3 Cyl. No.4 Cyl. No.5 Cyl. No.6 Cyl. Coil Speed miles/hr. Snap full Snap full Snap full Snap full Snap full Snap full Snap full Top Gear. open load open load open load open load open load open load open load Idling 2.0 2.2 2.5 2.6 2.85 2.3 3.85 Slow Running 2.4 2.9 3.0 4.0 3.85 3.05 5.0 10 3.3 3.1 3.05 3.15 4.5 4.6 4.6 4.2 4.8 4.8 5.6 4.2 6.0 5.7 20 3.8 3.25 3.65 3.9 4.6 4.6 4.85 4.6 5.0 5.2 5.7 4.25 6.25 5.85 30 4.0 3.4 4.1 3.95 4.65 4.65 4.7 3.8 5.1 5.3 5.75 4.75 6.2 5.75 Idling speed - 350 R.P.M. Slow Running - 6 M.P.H. | ||