PRIN. OF INTERNAL COMBUSTION ENGINES - OD1619 LESSON 2/TASK 3
(4) Thermostat Beat Ranges. A variety of thermostats are available to allow the
coolant to operate at different temperatures. The standard heat ranges available
are from 160 F (71 C) to 210 F (99.8 C).
(5) Coolant Bypass (figure 72 on the following page). The engine is designed so
that the water pump will circulate coolant within the water jackets whenever the
thermostat is closed. This is important to keep pistons and valves from
overheating even though the engine is below operating temperature.
FIGURE 72. COOLANT BYPASS.