1 - damper of the air supply distribution device; 2 - air sucked into the injection system; 3 - thermoelement; 4 - cold air flow; 5 - flow of warm air.
Controlled by a thermocouple in the mixing chamber of the air filter housing, the intake air heater distributor damper is designed to maintain the optimum temperature of the air intake by the engine. This is necessary for the following reasons.
- In cool weather, the quality of the working mixture is better if the intake air is already warmed up to the engine. Of course, at a higher ambient temperature, the heated intake air should no longer enter the engine, since warm air has a larger volume than an equal amount of cold air.
- Freezing prevention. Freezing occurs due to a pressure drop in the injection system while the engine is running, while part of the fuel evaporates and is significantly cooled. Because of this, the body of the injection system is cooled, and at temperatures from +3°C to +8°C, and high air humidity, a thin layer of ice can form in the injection system, which interferes with high-quality mixture formation.
Air filter for Bendix single point injection system. To control the performance of the wax thermostat (shown by the arrow in the left figure) direct a stream of hot air from a hair dryer at the sensor - the valve flap should move relatively quickly deeper (arrow on the right picture).
Elements of the intake air preheater:
- The main element of the intake air preheater is the mixing chamber.
- A snorkel is located in the mixing chamber (pipe branch) intake air with two inlets. Cold air enters through one port and heated air from the intake manifold preheat container through the other.
- A valve in the air filter housing snorkel mixes cold air from a single intake port with heated air from a preheat container on the muffler exhaust manifold so that the air entering the injection system is at the optimum temperature for mixture creation.
- The mixing chamber contains a wax thermostat connected to a spring-loaded valve.
- If the temperature of the air sucked in with the valve of the preheating container open is higher than +26°C, the wax in the shell starts to melt. At the same time, it expands and slowly closes the valve.
- When the temperature reaches +36°C, the valve completely closes the access of heated air and opens the passage in the suction snorkel for cold air.