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from flooding if the pump, engine, or pipes are below water line. With a rotary pump it is a good plan to have a cock or valve at the pump, or close to it, as in this way the pump can be primed, or oiled, through the cock without trouble. Both plunger and rotary or gear pumps should also be provided with a drain cock at the lowest point, from which all water may be drawn in cold weather to prevent freezing, and there should be
a test cock between pump and engine so that by merely opening this the operator may readily ascertain if the pump is operating properly.
The water-cooling system in the Ferro engines (illustrated in Fig. 68) is unique and is well worthy of consideration. In these motors there is no exposed piping or connections as the water from the intake is pumped directly into the water jacket by means of a plunger pump directly connected to the shaft. In the illustrations the system of circulation as well as the simplicity of the pump are plainly shown. After leaving the pump
the water is forced through a channel in the crank case and hence up to the jacket. Entering the water jacket the water divides and passes up on both sides of the exhaust port and then up and around the cylinder to the cylinder head, from which it passes into the exhaust manifold. It can then be piped either directly to a tank, to the outboard connection, or can be led into the exhaust pipe. At the lowest point in the water channel in the crank case there is a drain cock from which all water may be drained from the cylinder.
Almost as important as the vaporizing system is the lubrication equipment, for if allowed to run dry, or with too little oil, a gasolene motor will at once heat up and will soon be ruined beyond repair. If fed too much oil, carbon will accumulate in the cylinder, on the piston and valves, and will even choke up the muffler and exhaust, besides causing a disagreeable odor and excess of bluish smoke. Lubricators or oilers may be divided into three groups: gravity oilers, force-feed oilers, and grease cups. Gravity oilers consist of a tank or other receptacle to hold the oil, with pipes running to the various points of the motor requiring lubrication. They operate by the oil dripping through from the reservoir by gravity, and in order to aid in their operation a small ball check is usually placed at the top of the oil pipes. This class of oilers is in general use and they may consist of either a large tank from which numerous pipes lead, or may be merely independent oil cups. Several makers now have glass-bodied oil cups with several feeds, as illustrated in Fig. 69. For small or single-cylinder motors these oilers answer all require
ments, but they require frequent refilling and the best of them are apt to leak oil and become greasy and dirty.
Force-feed oilers are very different in principle and construction; they consist of a tank or receptacle for the oil, within which is a compact oil pump operated by a lever, pulley-wheel, or gears connected to the engine, and this pump forces the oil through the pipes to the proper points. As the pump will force the oil against high pressure there is no danger of the pipes becoming clogged or the oil failing to reach the bearing surfaces. On some portion of the oiler there are small tubes, enclosed by glass, through which the oil is forced in drops in exactly the quantity that it is fed to the engine. This acts as a sight feed, and by means of plungers, or screw adjustments, the flow of oil to
Oiler any or all pipes may be regulated to feed the proper amount. On large-size, multiple-cylinder, vehicle motors or any motor that operates for some time without continual observation, the force-feed system is a necessity, and although the first cost is more than for the gravity oilers the results are fully worth the additional outlay. An excellent type of this class of oilers is manufactured by the Detroit Lubricator Co. (Fig. 70), while those of the Osgood
Lubricator Co. are illustrated in Fig. 71. Grease cups are used on bearings, shafts, and smiliar places, and consist of a cup which is filled with grease that can be forced onto the bearings by means of a plug, or plunger, screwed into the cup (Fig. 75). For marine and stationary work these grease cups answer very well, but if the motor is provided with a force-feed lubricator or
a tank gravity-feed oiler it is better to oil the bearings by the regular lubricator pipes. The principal points for lubrication are the piston, piston-pin, connectingrod bearing, main bearings, and, in four-cycle motors, the gears, cams, and push-rods.
The proper amount of oil to be fed depends largely upon the size and speed of the engine and its age and care. A new motor will require more oil than one which has been operated for some time, while an engine that has become badly worn, and loses compression, may often ·