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).
Investigation into the gumming up of throttles on a Phantom III, caused by petrol residue.
| Identifier | ExFiles\Box 103\5\ scan0174 | |
| Date | 16th December 1938 | |
| To By.. from Rm{William Robotham - Chief Engineer}/GWH.{George W. Hancock - Head Chateauroux} Rm{William Robotham - Chief Engineer}/GWH.{George W. Hancock - Head Chateauroux}6/N.16.12.38. Re: Gumming up of Throttles. ------------------------- I was investigating at N. as to their troubles with sticking throttles, and I learnt that a Phantom III. had been in with the throttle valves stuck up, due to the residue from petrol. This was a car that had been in the Showroom for a short period and the trouble had developed during that period. Birkett at N. told me he had the Shell representative down over the job as Shell petrol had been used. In the conversation he said that with present day high grade petrols, if a tank was left with a small quantity of petrol in and was stored in a warm Garage, Showroom etc, a gum deposit would form, as also in the float chamber if petrol was left in there. He covered himself by saying they were carrying out tests to definitely prove this, and if they were able to do so, it would probably mean in the near future to warn Owners to either empty the tanks and carburetters, or else fill the tank up, if the car was going to be held up for a time. He gave the information that to remove the gum deposit, the best desolvers were: 1. Caustic soda. 2. Acetone. 3. Methylated spirit. I am waiting to hear further details. In the meantime I am of the opinion that we should instruct LeEvans to see that no petrol was left in the tanks or carburetters of chassis delivered from the works, also advise our Agents the same with show cars. GWH.{George W. Hancock - Head Chateauroux} | ||