(5) When the proper adjustment of each bearing has been obtained, clean the babbitt surface carefully and place a little lubricating oil on the bearings, also on the crank shaft; then draw the caps up as closely as possible, the necessary shims, of course, being in place. Do not be afraid of getting the cap bolts too tight, as the shim under the cap and the oil between the bearing surfaces will prevent the metal being drawn into the close contact. If oil is not put on the bearing surfaces, the babbitt is apt to cut out when the motor is started up before the oil in the crank case can get into the bearing. In replacing the crank case and transmission cover on the motor, it is advisable to use a new set of felt gaskets to prevent oil leaks.
III
THE FORD COOLING SYSTEM
Q. How is the engine cooled?
A. The heat generated by the constant explosions in the engine would soon overheat and ruin the engine were it not cooled by some artificial means. The Ford engine is cooled by the circulation of water in jackets around the cylinders. The heat is extracted from the water by its passage through the thin metal tubing of the radiator, to which are attached scientifically worked out fins, which assist in the rapid radiation of the heat. The fan, just back of the radiator, sucks the air around the tubing through which the air is also driven by the forward movement of the car. The belt should be inspected frequently and tightened by means of the adjusting screw in the fan bracket when necessary. It should not be too tight, however. Take up the slack till the fan starts to bind when turned by hand.
Q. How does the water circulate?
A. The cooling apparatus of the Ford car is known as the thermo-syphon system. It acts on the principle that hot water seeks a higher level than cold water. Consequently when the water reaches a certain heat, approximately 180 degrees Fahrenheit, circulation commences and the water flows from the lower radiator outlet pipe up through the water jackets, into the upper radiator water tank, and down through the tubes to the lower tank, to repeat the process.
Q. What are the causes of overheating?
A. (1) Carbonized cylinders; (2) too much driving on low speed; (3) spark retarded too far; (4) poor ignition; (5) not enough or poor grade oil; (6) racing motor; (7) clogged muffler; (8) improper carburetor adjustment; (9) fan not working properly on account of broken or slipping belt; (10) improper circulation of water due to clogged or jammed radiator tubes, leaky connections or low water.
Q. What should be done when the radiator overheats?
A. Keep the radiator full. Do not get alarmed if it boils occasionally, especially in driving through mud and deep sand or up long hills in extremely warm weather. Remember that the engine develops the greatest efficiency when the water is heated nearly to the boiling point. But if there is persistent overheating when the motor is working under ordinary conditions, find the cause of the trouble and remedy it. The chances are that the difficulty lies in improper driving or carbonized cylinders. Perhaps twisting the fan blades at a greater angle to produce more suction may bring desired results. By reference to the proper division of this book each of the causes which contribute to an overheated radiator is treated and remedies suggested. No trouble can result from the filling of an overheated radiator with cold water, providing the water system is not entirely empty, in which case the motor should be allowed to cool before the cold water is introduced.