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).
Visit to Rover detailing the development of 4-cylinder engine inlet ports and carburettor systems.
| Identifier | ExFiles\Box 127\2\ scan0178 | |
| Date | 5th August 1940 | |
| To Rm.{William Robotham - Chief Engineer} from Jnr.{Charles L. Jenner} Jnr.{Charles L. Jenner}1/JH.5.8.40. 1091 Visit to Rovers. 4 Cylinder, 2 Inlet Ports V.{VIENNA} 4 Ports. They went to 4 inlet ports so that they would be in a position to control distribution by various design of pipes. The robbery in filling each cylinder caused by the overlapping of the inlet valves is considered to be of little or no detriment. However if we analyse their development we find that the first pipe made was a theoretical ideal, 4 ports with 2 pipes and a duplex Solex carburetter. To make this function in all respects it was found necessary to have a very large balance hole. Because of this they reasoned that this became really one carburetter with divided branches each side. The Solex was abandoned in favour of the horizontal S.U., the former proving a hateful instrument. 1st. stage - DUPLEX SOLEX. The second stage having been left with the 4 ports on the head was the horizontal S.U; this was satisfactory and pleasing in all respects on the test bed, but when put on the road could not be got under the bonnet, owing to the room taken up by the air silencer. The third stage the fitting of the downdraught S.U. has resulted in the 3 different pipes. Rovers dislike the downdraught carburetter mostly because of the horizontal piston. This is the pipe they sell. | ||