There is a switch attached to the accelerator pedal bracket (special bracket) which energizes the solenoid at full throttle. The door which is opened by the elec solenoid is the one which actually lets in fresh air to the air cleaner. The vacuum actuated door on the outside is really more for show. But it looks really good. Of any functional fresh air ever madeon the planet, the 70-72 Cowl Induction hood is the best.
[This message has been edited by DZAUTO (edited 12-22-1999).]
Then, Tom, why is it that almost every picture I have seen of 70-72 Chevelles with CI hoods, the flapper is OPEN, even though the car is parked? Do some people just prop theirs open because it's so difficult to get these devices to work properly? I'm asking because as soon as I repaint my Chevelle, I'm adding a flapper to my CI hood and I'm debating whether to go the extra expense to make it functional.
With the engine shut off, the outer cowl induction flapper door will remain OPEN. The door requires engine vacuum to close. At low vacuum conditions, like full throttle or the engine shut off completely, the door opens.
Larry is on the money, the outer is vacuum operated, and like he says, when you accelerate hard or the engine is off, then the outer door opens. I probably didn't explain very well. There are TWO doors on a CI hood, the outer which is vacuum operated, and the inner which is electric. The outer door opens when manifold vacuum drops real low, such as acceleration hard. But the inner door ONLY opens when you put the go pedal to the floor to engage the switch which energizes the solenoid for the inner door. And as I said, this is the one which lets in the fresh air. The outer door is just a flapper that says "look at me I'm bad". And generally speaking, that's correct.
Tom, though I'm no expert, owning a '69 and all, I'm enough of a student of Chevelles to know there's 2 doors on a CI hood. I think there's a sizeable contingent who don't realize that fact. It's just not the same as for a '69 CI Camaro where there's no outer flapper, there's just the inner solenoid operated door. I've mentioned this to a few of my friends looking at Chevelle's that if the CI door is closed while the car is sitting it's something to ask about.
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