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 from the American branch discussing choke valve, detonation, and overheating issues on the Phantom engine.
| Identifier | ExFiles\Box 72\2\ scan0055 | |
| Date | 2nd November 1925 | |
| ROLLS-ROYCE OF AMERICA, INC. SPRINGFIELD, MASS. 48991 Oy23-E-11225 November 2nd, 1925. Mr. E.{Mr Elliott - Chief Engineer} W. Hives, Rolls-Royce, Ltd., Derby, England. Re Phantom engine Dear Hives: Since I wrote you last we have been forced back to the use of the choke valve in the exhaust, by the consideration that we want to follow England as closely as possible, and the fact that we must make up our minds quickly about what we want to start doing, as our program is becoming more and more urgent as our deliveries increase. The inserted-tube jacketted intake pipe has not been tested yet. The choke valve has gradually been ground down to 1-3/8" diameter, and detonation is now much less than it was. The starting on a cold morning is excellent. The chief trouble (which was largely overcome by omitting the choke valve) is that, so long as the water temperature exceeds 75° Cent. the engine still insists on having convulsions after you switch off. This is the more surprising as it shows no signs of distress while running. Have you considered forcing the water into the rear cylinder block opposite No.6 cylinder instead of No.4? With the thermometer fitted in the radiator intake and therefore measuring the mixed water from all 6 cylinders and with no "riser" above the cylinders as on the Silver Ghost it is difficult to tell | ||