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 of make ratio versus distributor speed for a standard distributor at various primary gap settings.
| Identifier | WestWitteringFiles\L\2April1924-June1924\ Scan109 | |
| Date | 4th April 1924 | |
| MAKE RATIO-SPEED CURVES. OF R.R. STANDARD DISTRIBUTOR. MAKE RATIO. DISTRIBUTOR SPEED R.P.M. NORMAL SPEED 720 R.P.M PRIMARY GAPS. a.{Mr Adams} .010" b. .018" c. .026" a .65 b .55 c .45 H.E.W 4-4-24 E.F.C 4/4/24 | ||