The Vaporizing Of Paraffin for High-Speed Motors
(Electric Ignition Type)

SUPPRESSING EXPLOSIVE ACTION. 55 consequently there are under these conditions two reasons for diluting the ingoing heated mixture, either with a water spray or with inert gas. The latter method, how- ever, is not suitable for engines having a cylinder diameter exceeding 13 or 14 indies, and for engines of this and larger sizes the best results can only be obtained by a water spray injection, as shown in Figs. 39 and 40, and if much exceeding this, also by water jacketing the piston head ; and even then, if the circulating water is allowed to get much above 120°, whatever the means adopted, when using paraffin, there will still be a more or less violent explosive action, resulting also in a con- siclerable falling off in the power of the engine, compared with what it is capable of developing for the first quarter of an hour or so after being started up. The worst feature associated with the practice of using a water injection, especially in cylinders of less than 6 to 8 inches diameter, is the liability to quench the mixture when running on reduced throttle opening, itnless means are provided as by a fioat-feed carefully regulated jet to avoid this ; another drawback to the injection method if used in connection with an engine in continuous service with impure water, is the liability to fouling of the igniter points, piston head, and walls of the combustion space with hard calcareous deposit. As a case in point, in an installation of three 3-cylinder (13 inches x J8 inches) vertical engines coming under the writer’s observation, that were required to run under practically full load by day and three-quarter load by night, the igniters had to be changed once or twice every week, and the combustion chambers scraped after a run of at most six weeks, the vaporizers being