Air Cleaner Vacuum line connection?

If you have the standard v2 air cleaner there should be one flapper door for the heat riser, the air intake. When the engine is cold the flapper should be closed which allows air flow from the heat riser coming off the exhaust. This heats the incoming air to help a cold motor warm up faster.

When the engine heats up a bimetal heat switch kicks on which shuts the vacuum signal to the heat riser flapper and closes the heat riser down so cooler air flows into the intake.

There should be a hose going from the flapper motor to a metal vacuum switch with 2 ports one port is taken by the flapper hose the other to full manifold vacuum source.

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The vacuum source is a port on the vacuum tree behind the carb on the intake manifold, near where you also get vacuum for the brake booster and transmission vacuum modulator (if so equipped).

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