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).
Graph showing the Make Ratio-Speed curve for a new standard battery ignition contact breaker.
| Identifier | WestWitteringFiles\S\June1928-August1928\ Scan113 | |
| Date | 27th July 1937 | |
| RR STANDARD BATTERY IGNITION. MAKE RATIO - SPEED CURVE OF NEW STANDARD CONTACT BREAKER TO LEC 2460. MAKE RATIO. .1, .2, .3, .4, .5, .6, .7 DISTRIBUTOR SPEED rpm. 200, 300, 400, 600, 800, 1000, 1200, 1400, 1600 27-7-37 | ||