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).
Letter detailing experimental results for a starting carburetter.
| Identifier | ExFiles\Box 66\3\ scan0225 | |
| Date | 28th December 1927 | |
| ROLLS-ROYCE OF AMERICA, INC. SPRINGFIELD, MASS. 48280 RECEIVED STAMP JAN 11 1928 Mr. Hives for your kind perusal and comment please OY5.R.12.28.27 December 28th, 1927. [Signature] Jan 11. 28 Mr. Thomas Nadin, Rolls Royce Ltd., Derby, England. Dear Nadin: RE STARTING CARBURETTER - SECTION 5280 EXPERIMENTAL RESULTS You will have received my letter of December 23rd with prints of sketches 169, 170 and 171 and also a copy of my note of December 27th with a chart of the pilot jet openings. We can now begin to give you some experimental results: - (1) The baffle and drain of SK-170 does not seem to be an advantage and in view of the fact that we have been setting the Phantom starting carburetter very much too rich, the drain and baffle have not been proved necessary. We believe that without them we can get a start at any temperature down to O-F with between 1/4 and 1/2 turn on the existing pilot jet, and under these conditions we get quite a good spraying effect and not very much more tendency to "over-choke" than we had on the S. Ghost. (2) We are issuing a bulletin to the depots calling for a setting of the pilot jet not exceeding 1/2 turn. This we believe will be a certain insurance against over-choking and a slight help towards preventing cold knocks and so long as reasonable engine and gearbox oil are used and the throttle is made to close properly, there will be no difficulty in starting. (3) We have tried the scheme shown on SK-171 for supplying additional oil to the engine when starting by means of a connection from the rocker feed to a small hole or groove on the plug of the pilot jet cock. Test for three mornings on MX{John H Maddocks - Chief Proving Officer}-3 together with test at intervals during the day, has proved that this method effectually stops cold knocking. (Continued) | ||