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).
Engine development, focusing on induction systems, carburetters, manifolds, and pistons.
| Identifier | WestWitteringFiles\S\September1928-October1928\ Scan191 | |
| Date | 26th October 1928 guessed | |
| contd :- -5- With regard to the other tests we have carried out we consider the six port induction system gives better distribution than our previous four-port engines. The vertical Claudel Carburetter supplying through the underfed slot pipe gave excellent full throttle distribution with the spray nozzle removed from the slot. This particular carb. could only be fitted with the barrel throttle axis at right angles to the distributing manifold consequently the distribution when throttled down was not good due to the mixture having a bias to the one end of the manifold. We are looking forward to good distribution results with the new RR. carb. combined with a slot type pipe. As requested we are fitting up two vertical carbs. each to supply three cyls. as with the F.{Mr Friese} engines. The present exhaust manifold is very noisy, the noise of the exhaust discharge impulses being clearly heard through the thin manifold. A cast manifold we consider is necessary as apart from noise we experience considerable distortion of the present one. We are persevering with other items such as pistons and valve gear as it is these we have found in the past demand the most attention when on production in order to obtain quietness of operation. We are concentrating on the single bolt pedestal pistons with three plain rings and a perfect circle ring and consider they should overcome a lot of the present production trouble due to distortion by the gudgeon pin fitting. With regard to valve springs, we experience con- contd :- | ||