1916 Antique Cars Index
Q. What types of pumps are used to circulate oil?
A. Two forms of pumps are used to circulate oil, the gear form which is shown at Figs. 119 and 121 and the plunger pump clearly outlined at Fig. 122. The gear pump consists of a pair of spur gears, having large teeth, meshing together in a closely fitted metal case. One of the gears serves as the driving member and is turned by any suitable mechanical connection with the engine crankshaft or camshaft. The plunger pump is usually cam operated, as indicated at Fig. 122, because it works with a reciprocating motion instead of a rotary movement. Both forms outlined are positive though the plunger form is capable of exerting more pressure on the oil than either the spur gear or eccentric forms also widely used.
Q. Why should oil supplied to engines be carefully regulated ?
A. It is imperative to insure efficient engine action that the oil be supplied in measured quantities that will be just right for the conditions under which the power plant is operated. If the lubricating oil is introduced in excessive quantities a considerable portion will be forced into the combustion chamber, where it will be burned by the excessive heat present at that point and produce carbon deposit in the interior of the cylinder head. When an engine is supplied with too much oil the surplus will escape at all possible bearing points and the wasted lubricant performs no useful service. If the oil is not supplied in sufficiently large quantities the bearings will heat because of the friction between their parts and some of the engine power will be lost. If the oil supply is interrupted through accidents, the part may heat up sufficiently so that the bearings will be burnt, cylinder and piston walls scored and other damage done.
Q. How can oil supply be regulated?
A. One of the advantages of the constant level splash system of lubrication is that the amount of oil required is determined by experiment at the factory and the motorist does not have to regulate the oil feed to any extent. The operator's responsibility ceases when the oil container has been filled with a sufficient quantity of good engine oil. On some of the individual pump mechanical oilers the stroke of the pumps may be varied to alter the oil feed. Sight feed lubricators are often provided with needle valves to regulate the amount of oil passing through the orifice they control in a given unit of time.
Q. Describe some typical lubrication systems used on high grade cars.
A. The oiling system of the Packard six cylinder motor is clearly outlined at Fig. 124. In this the oil is carried in a sump formed integral with the crankcase and is taken from that point by a pump and delivered to a manifold pipe extending along the side of the motor crankcase. This manifold communicates with the main bearings, as well as to the timing gear assembly at the front end of the motor. The crankshaft is provided with drilled passages so the oil supplied by the oil manifold lubricates the connecting rod big ends after it passes from the main bearings. The cylinder interiors, pistons, valve plunger guides and other parts are thoroughly oiled by the oil spray always present in the crank case. A manometer or pressure gauge is carried on the dash board and is attached to the end of the motor oil manifold. This indicates at all times if oil is being delivered to the bearing points. If the pressure of oil becomes too great in the manifold as sometimes occurs at high engine speeds, a relief valve is provided which permits the excess lubricant supplied by the pump to bypass back into the crankcase interior.
The system of lubrication employed on Packard trucks is shown at Fig. 123. In this the oil is drawn from a tank by an oil pump and forced through the sight feed on the dash, back to the crankcase interior, where it collects in the front and rear crankcase compartments to a level indicated by the petcock screwed into the sides of the crankcase. The interior of the engine is thoroughly lubricated by the splash system.
In the Pierce Arrow cars practically the same arrangement as used in the Packard six cylinder and several other leading cars is used. This system is depicted at Fig. 125 and involves the use of a gear driven oil circulating pump having its suction side connected to the sump at the bottom of the crankcase and its delivery pipe to a manifold which goes to the main bearings of the drilled out crankshaft. A feature of this system is the use of an oil strainer or filter screen on both suction and delivery sides of the pump. Both of these screens may be readily removed for cleaning purposes and insure the delivery of only perfectly clean oil to the bearing points. Two petcocks are provided on the side of the crankcase. The one at the bottom is a drain cock through which the sump may be emptied at any time while the testcock indicates if the oil level in the sump is sufficiently high.
This figure and figures 123 and 124 didn't reproduce well. They were very poor gray-scale images. Fig. 125.-Oiling Method Used in Lubricating Pierce Arrow Six-Cylinder Power Plant.
Q. How can oil be introduced to the crankcase interior in emergencies ?
A. Practically all power plants utilizing the constant level splash or manifold supply systems in which the oil is carried in a container integral with the crankcase have a filler tube or funnel that communicates directly with the crankcase interior, through which the lubricating oil is poured. In some forms o f power plant where t h e feed is by individual p u m p mechanical oilers that are set for normal operating conditions it is s o m e times desirable to provide a hand operated pump of the simpIe plunger type that may be used to draw oil from an auxiliary tank and force it to the crankcase interior in order to help out the lubricating system under abnormal operating conditions such as speeding and long stretches of low speed gear work where the engine must run fast and pull hard. A simple form of oil pump adapted for this purpose is clearly outlined at Fig. 126.