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 discussing the experimental design and proposed winter testing of a new priming jet system and its operating mechanism.
| Identifier | ExFiles\Box 74\2\ scan0053 | |
| Date | 15th November 1921 | |
| Oy3 - G 151121 Sheet #4. The latest form of jet in which we get still better spraying and therefore hope to get a start with a smaller flow of fuel, is shown in unnumbered print A enclosed. This is only in the experimental form and will need modifying to ensure that if the jet blocks it can readily be cleaned and reset to the same opening. It will be noticed on print A-1371 that the dimensions of the operating mechanism have been made larger than the existing mechanism for operating the priming device. This is to make the parts suitable for foot operation which we find is used by most drivers and for which our present priming handle is not adapted. To reach the present priming handle in a body with a long cowl is quite difficult. Furthermore, the cock has been made large to avoid leakage while keeping the gas passage as large as possible, and the plug has been tapered 1 in 4 to avoid sticking, which is very prevalent with the existing cocks, and was a difficulty met with on the experimental pilot jets sent by Mr. Hives. The 1 in 4 cocks act excellently and do not stick. It will be noted from what has been stated above that both the induction pipe and pilot jet are in an unsettled state and we do not consider that either of them has reached a stage where it is possible to state definitely that they will meet American winter conditions. Knowing the variations between individual cars, the variations in quality of gasoline and lubricating oil, and the exceedingly low winter temperatures of certain parts of this country and Canada, we consider that it will be necessary to fit these devices to at least 50 cars running in various parts of the country, and gain experience through this whole winter before we can say that they will successfully meet present-day conditions. Yours truly, MO/G ROLLS-ROYCE OF AMERICA, Inc. Per M.{Mr Moon / Mr Moore} Olley Enc. (2 each of the following prints:) XA-1206/7 A-1357 A-439 A-440 A-1312 A-1371 Print A (unnumbered) | ||