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).
Instructions for modifying the 25/30 governor to improve slow running with the deturbulated cylinder head.
| Identifier | ExFiles\Box 101\3\ scan0073 | |
| Date | 7th June 1937 | |
| By.{R.W. Bailey - Chief Engineer} from Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} c. Hs.{Lord Ernest Hives - Chair} c. E.{Mr Elliott - Chief Engineer} c. RHC.{R. H. Coverley - Production Engineer} c. Mx.{John H Maddocks - Chief Proving Officer} Rm{William Robotham - Chief Engineer}/Swd113/R.7.6.37. 25/30 SLOW RUNNING. Will you please modify the governor which is now on production with the deturbulated cylinder head, in accordance with our findings, as follows:- To improve the slow running, by virtue of running with a later timing at the idling speed. We should like this to be retrospective for all the units with the deturbulated head. (1) E.60879 governor frame giving a 30% advance. Existing units with EE.2832 frame (20% advance) can be modified by machining the stops to be identical with E.60879 (30° advance). (2) Governor spring to E.52103 but in 18 SWG (.048 dia) and spring ends at 90°. (3) Reduced hand control range LeC.5697, a similar mock-up scheme having been tried. (4) New BAL marking on the flywheel to be 5° before TDC. ------------ The specification for the Works should be that the governor actuating spindle be perfectly free, likewise the governor levers. The spring tension should be just sufficient to return the governor weights, any excess initial tension detracts from required rapid advance rise above idling speed. The governor characteristic is as follows:- | ||