Quote:
Originally Posted by blue71ta
Bob,
you actually had it right the first time. Here's a pic of my original 455 HO RA air cleaner with the original, white-striped hoses. The short one that comes off the tee in the front is the one that goes down to connect to the vacuum source on the intake manifold (the fitting that you have circled in your engine pic).
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If you plumb the vacuum lines like that, and like the black car was plumbed, one of the vacuum actuators will be closed at all times when the engine is running. These vacuum actuators are normally open, and close when vacuum is applied. That means that as soon as manifold vacuum is generated the actuator on the vacuum source side of the air inlet thermal vacuum sensor will close the flapper and as long as vacuum is present the flapper will remain closed and prevent fresh air from entering the engine. Also, the only way to get both vacuml actuators to work in unison is to have them both plumbed to the same side of the air inlet thermal vacuum sensor.
I need to do some more experimentation in the morning, but I think the air inlet sensor is normally open which lets the vacuum go through the "switch" so to speak thereby closing the flappers in both snorkles. Once the vehicle comes to operating temperature, the switch (air inlet sensor) closes thereby preventing the vacuum from passing through it and to the actuators. In the absence of vacuum, the flapper doors open and fresh air enters the combustion process.
This sounds good on paper and i think I am right.