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 specifications for 20 HP steering conversions to achieve a lower over-all ratio.
| Identifier | WestWitteringFiles\S\March1928-May1928\ Scan152 | |
| Date | 7th May 1928 guessed | |
| 20 H.{Arthur M. Hanbury - Head Complaints} P. STEERING CONVERSIONS TO GIVE LOWER OVER-ALL RATIO. | | 1 | 2 | 3 | 4 | 5 | 6 |---|---|---|---|---|---|--- | SERIES | PREVIOUS TO F | To 150 IN J | CONVERSION Cols 1 & 2 | FROM 151 IN J | "M" | CONVERSION Cols 4 & 5 | LEAD | .930 | .930 | .750 | .700 | .700 | .700 | PITCH DIA. | 1.035 | 1.035 | 1.035 | 1.500 | 1.500 | 1.500 | Nº OF STARTS | 3 | 3 | 3 | 3 | 3 | 3 | HELIX ANGLE | 15º - 57' | 15º - 57' | 12º - 59' | 8º - 27' | 8º - 27 | 8º - 27' | ROCKING SHAFT | 1.750 | 1.750 | 1.750 | 1.400 | 1.400 | 1.400 | PEND LEVER | 10.00 | 10.650 | 10.65 | 10.000 | 8.250 | 8.250 | SIDE STEERING LEVER | 7.500 | 8.000 | 8.000 | 9.000 | 8.00 | 9.000 | LEVERAGE | 8.9/1 | 9/1 | 11/1 | 11.3/1 | 12.2/1 | 13.7/1 | TURNS OF WHEEL | 1.7 | 1.8 | 2.2 | 2.1 | 2.25 | 2.5 | LOCK ANGLES | L 41º R 36 1/2 | L 41. R.{Sir Henry Royce} 40. | L.41 R.40 | L 41 R 33 | L. 41. R.{Sir Henry Royce} 33 | L.41. R.33 | SIDE STEERING TUBE DETAILS | F.51865 UNEQUAL SPRINGS | F54584 SPRING F51863 11,50 LBS/1" .150 TRAVEL | N.SCH 2308 SPRINGS F.54759 600-LBS/1" .400 TRAVEL | N.SCH 2308 SPRINGS F54759 600 LBS/1" | N.SCH 2308 SPRINGS F54789 750 LBS/1" | N.SCH 2308 PROBABLY F54754 900 LBS/" | ||