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).
Carburetter and induction system development, discussing 'hot spots' and exhaust heating.
| Identifier | WestWitteringFiles\S\June1928-August1928\ Scan003 | |
| Date | 12th June 1928 guessed | |
| contd :- -3- It would appear that the best position to 'ho/t spot' an induction system supplying six cylinders from a vertical carburetter would be round the 'Tee' junction of the uptake and horizontal pipes. At this point the wet mixture impinges before it changes its direction of flow along the horizontal manifold. In view of the tests we have carried out we do not think water heating, even with the new carburetter and improved induction system, will give us sufficiently quick warming up from cold to compare favourably with the high standard we have established on the standard cars. We do think however that there is considerable possibility of making exhaust heating sufficiently rapid without the use of a butterfly valve in the exhaust down pipe, by means of an ejector or venturi to equal our present system. In that case we should probably have to incorporate a valve in one of the hot spot pipes which reduced the exhaust circulation at full throttle in order to limit the temperature of the hot spot. Probably a small hot spot and an adjustable hot air intake for use in cold countries as suggested by Mr. Royce would, when used with the improved carburetter and induction, give good results. We will continue experiments with a small size vertical carb., to reproduce more nearly the conditions obtained with the vertical constant suction carb; and various dimensions of slot in the underfeed pipe to give the best cold distribution. We may find a narrow slot is not necessary with a vertical carb. giving a well diffused mixture and will work with the object of finding the best dimensions and shape. Hs{Lord Ernest Hives - Chair}/A.C.Lovesey. | ||