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).
Summary of the 20 HP steering position, comparing J and M series geometry and steering ratios.
| Identifier | WestWitteringFiles\S\March1928-May1928\ Scan151 | |
| Date | 1st May 1928 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to BJ. Hor. c. to E.{Mr Elliott - Chief Engineer} DA.{Bernard Day - Chassis Design} c. to DY.{F R Danby} OY. ORIGINAL Hs{Lord Ernest Hives - Chair}/RmS/LG2. 5. 28. 20 HP. STEERING. V5430 We attach a summary of the 20 HP. steering position. Cars up to the first 150 in J.{Mr Johnson W.M.} series cannot be fitted with the improved geometry to M.sch.2401 because the pendulum lever is on the inside of the frame. The present std. for replacements is the .750 lead nut - this gives a steering ratio of 11/1 and we have had no complaints so far that could not be satisfied by this nut, if any occur it will be necessary to provide a new steering box having the .700 lead and then the improved geometry can be added. With reference to 'M' series which is at present going into production. On this we have the improved geometry to M.sch.2401 and an overall steering ratio of 12.2/1. We can, however, by reverting to the length of steering lever used in J.{Mr Johnson W.M.} series, get an overall steering ratio of 13.7/1 without altering the geometry, and at the same time considerably improve the shape of the side steering tube. We should therefore like to go ahead immediately with column '6' on 'M' series as being the best that we know of, all the parts of this having been tested out in various combinations. Will you please let us know if you agree. We may slightly modify the s.s. tube springs to prevent undue sponginess as on the 40/50 HP. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||