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).
Technical letter discussing modifications and issues with governor unit 21-G-IV, including dirt contamination and oil leaks.
| Identifier | ExFiles\Box 5a\4\ 04-page085 | |
| Date | 1st August 1934 | |
| C.W. Hancock, Esq., Hotel de France, Chateauroux, Indre, France. Hs{Lord Ernest Hives - Chair}/Les.7/KW.1:8:34. 21-G-IV. Re your report of the 27th inst. Since the 17th of this month, R.H.C. has been instructed to build a new governor unit for 21-G-IV. This unit is to have 3 alterations to give protection against dirt getting under the valves. However, now that SpectreCodename for Phantom III is appearing we shall have to continue testing the production unit. We will send you out a new hand control unit to replace the one that you say has been very badly produced. As this valve is always open when the car is going there is not the slightest need for this valve to have a good bedding, although we must certainly condemn bad workmanship. In order to make this valve less sensitive to dirt we want to make the seat as narrow as possible. We have had definite proof that dirt causes more trouble with a wide seat. The fluff which you have found in 21-G-IV unit is very serious, as this particular unit was cleaned with the production filter in series, the valves also being set on production. There is therefore every reason to believe the other production units are similar. Can you let us know exactly where the fluff was and which valves were affected by dirt. Loss of Oil from Oil Drain. You reported that 28-EX governor unit leaked oil if filled to the top level. Recently production ran into the same trouble to a much more severe degree. On Dyno. 2 units actually emptied themselves. This has been overcome by drilling the oil release orifice in a new position. We enclose a drawing showing the alteration. | ||