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).
Experiments with different carburettor and manifold setups and their impact on power distribution.
| Identifier | WestWitteringFiles\Q\February1927-March1927\ 35 | |
| Date | 2nd February 1927 guessed | |
| contd :- -3- (3) Carb. with two throttles feeding two 3-cyl. manifolds (Fig. 3) The distribution and power were very bad at all speeds and a reliable power curve could not be obtained. (4) Straight manifold with one carb. at the end - tested on 20 HP. With this system the distribution was again considerably influenced by the throttle position and speed. At high speeds the cyls. most remote from the carburetter were excessively rich. This characteristic reversed as the speed decreased. (5) Similar system with a carb. at each end similar to that tested on F.10. The distribution was improved but the disturbing influence of the throttle position was still very evident. (6) Hispano type pipe with the Duplex Hispano carburetters. At low speeds the distribution was good but very poor and erratic at speeds in the region of 2000 r.p.m. The difference is credited to the different arrangement of ports which we have to the Hispano. It was found during these tests that the distribution was not a question of pipe only but depended to a large extent on the carburetter. Different models of the Claudel carb. were tried on the Hispano type pipe and considerable variation in results were obtained. With the Claudel the effect of the position of the air intake was very marked. As a result of these experiments described briefly above, and others which have given only negative contd :- | ||