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).
Vehicle performance issues and modifications, including vapour lock, steering lock, and petrol systems.
| Identifier | ExFiles\Box 90\5\ scan0051 | |
| Date | 2nd September 1935 | |
| -2- Ha/Rm.{William Robotham - Chief Engineer}12/RH.{R. Hollingworth} 2.9.35. Apart from the re-starting difficulty, Hancock's modifications to the petrol system appear to have overcome the vapour lock trouble. This means that the first SpectreCodename for Phantom IIIs could be expected to give satisfactory results with regard to petrol supply if the simple modification of moving the filter outside the frame was carried out to the existing system. We do not dispute that in the future it may be found desirable to move the petrol pump too, but we should not recommend this for the first cars because it has not been tried out and may produce its own complications. On the other hand, the filter in the altered position has run 10,000 miles. We think the tests on the Stelvio have shown that it is imperative that we have some automatic operation for the shutters in the bonnet sides, also that we fit a more efficient fan to the next car to go to France. On the whole we were disappointed with the steering lock of the SpectreCodename for Phantom III on the Stelvio. We had to reverse on several of the bends, and generally speaking it was quite a feat of skill to get round many others on one lock. Possibly the best permissible lock has not been obtained on this car, and we will measure it up when it gets back. Any improvements in this respect will, however, make it a much more desirable Continental car. The SpectreCodename for Phantom III has of course a better turning circle than a Phantom. The Stelvio, though a great number of people ascend it as being the highest pass in Europe (over 9,000 ft.) has abnormally sharp bends, more so than any other main road pass we have encountered. BENTLEY. Before leaving England we arranged for an alternative petrol system for this car, having the filter outside the frame as on the SpectreCodename for Phantom III. We started out with the standard arrangement connected up. Signs of vapour lock were experienced after running at high speed on long, straight stretches. On changing over to the filter outside the frame, all signs of vapour lock disappeared and no further trouble was experienced. | ||