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).
Page discussing engine induction systems, carburettor configurations, and fuel distribution improvements across various engine models.
| Identifier | WestWitteringFiles\T\2January1929-June1929\ Scan116 | |
| Date | 7th February 1939 guessed | |
| contd :- -4- but we have not had exeprience with this on our cars and cannot say we like such a scheme. Very good distribution resulted with the induction system used and we have noticed that good distribution is more easily obtainable with one choke to three cyls. than with six cyls. drawing from one carburetter. This we found on the 20 HP. engine when comparing it with the Lorraine and also on the early Phantom which we tested with two RR.CH. carbs. The Hispano engine using a similar scheme was particularly good and only needed water heating. The reason xxxxxx seems to be that with a three cyl. manifold we avoid alternately changing the direction of flow in the distributing pipe which takes place in a manifold common to all the six cyls. and so is less liable to fuel deposition. Such a system on the SS.{S. Smith} engine, with its initially better distribution due to the six separate ports and the better volumetric efficiency afforded by the larger valves, we should expect would give good results with regard to still better acceleration. It will be remembered we shewed by experiment on the 20 HP. that the beneficial effect of larger valves and longer duration of valve opening was more than proportionally increased by employing a low induction pipe depression. It must not be imagined from the above xx notes that we advocate static carburetters for our car work because we feel that such carbs. will not give us the consistent low speed xxx pick up under all conditions which is such a characteristic of Rolls-Royce cars. These tests with the Solex have however shewn us what can be gained by contd :- | ||