MANY comprehensive papers have been presented on the various phases of the cooling problem. Macy O. Teetor's paper2 on “Cylinder Temperature” and L. P. Saunders' paper3 on “Radiator Development and Car Cooling” are representative of these.
The treatment of heat in an automotive vehicle presents many complex technical problems but the customer, who understands none of the technicalities, is directly aware of the results. He judges by: (1) how long the engine performs well, (2) how much oil it uses, (3) how often the radiator needs filling, (4) how much noise the fan makes, and so on.
Throughout the entire cooling system, the basic problem is one of rates of heat flow. Temperature balances are reached only when the heat lost by a given spot or system equals the heat absorbed. To have a balance temperature at a safe point, the rate of heat loss must be such that the temperature differential between hot and cold medium need not be too great.
High water velocities are frequently necessary to “scrub” out points where steaming tends to occur. Water pumps serve not only as a circulator within the engine, but also as a train of dump cars hauling B.t.u.'s to the radiator. Water-pump capacity determines the temperature rise of coolant through the engine.
Corrosion in cooling systems is due largely to air being drawn into the coolant at the pump packing or seals. Fan noise is a problem not limited to passenger cars.