Air Intake Pre-Heating
There are two basic functions which this system controls; load dependent function, and temperature control function. They operate as follows:
- During load dependent control function, if the throttle flap is closed or only slightly open, with engine running, the high vacuum moves the diaphragm and releases the hot air supply by means of the regulating flap. If the vacuum drops when accelerating, the diaphragm adjusts the regulating flap so that the hot air of the intake air decreases until the engine finally receives cold air only.
- During temperature control function, the bi-metal valve remains closed as long as the intake air has a temperature of less than about 132°F. At this time, unrestricted vacuum is applied in the diaphragm box. Hot air is fed to air intake by diaphragm and hot air regulating flap. If temperature reaches 132°F, valve opens and outside air flowing in reduces the vacuum. The regulating flap in air intake manifold then shuts off the hot air supply independent of the throttle valve setting. This provides temperature regulation of the intake air during all operating conditions.