Fresh Air ducts

[Pomorza]

Hello all

So cruising the junkyard recently I found a fresh air duct (the ones in the front of the Z that goes into the fender). Well I pulled it off and placed it in the Z this morning. Here's a question though. Exactly what does this thing do and how does one control its movements? Its kind of a bad idea to install things before you know what they do but hell it's held on by a bold so.

Thanks

Jan

[Bonzi Lon]

The black elbows? Right? If 76 is like the 73. At speed, they direct air into a closed tunnel under the fender that runs into the cabin. You control the flow by the vent knob which opens & closed a flap on the duct. Look up under the dash to see the flapper.

If you don't have any air movement when open, it could be clogged. The driver's side of mine is stopped up with a rodent nest. I would suggest, and have seen, a screen over the entrance of them to prevent just that.

Bonzi Lon

[TomoHawk]

The air 'tunnel' is where the fender meets the top of the inner fender (at least on my '78.) It has a rectangular cross-section and you can see it if you take out the inner fender/splash guard. On my '78, they don't have the elbow because air is 'scooped' from below by the lower-front edge of the splash guard (it hangs down a little to 'scoop' air.) I was considering closing this up to keep water from splashing behind the headlamps and adding the plastic elbows.

[tlorber]

Has anyone ever put in some kind of cabin filter? Either in this duct or anywhere else in the plenum?

[alternativez]

A cabin filter is a great idea! I recall my '70, way back when I was young, and it was new, would refresh the cabin with snowflakes. Running the blower would actually pull *fresh* outside air into the cabin, and cool it fairly well. The ducting through the unibody seemed a practical and rudimentary way to use the hollow structure, but as I have experienced in other cars, such as my 635, that is an area which will capture and hold moisture and dirt, which makes it prone to rusting at a very critical place. As I'm restoring a '70 Z now, I've thought of eliminating that feature and filling the hollow with structural foam. The air flow was nice back then when A/C was considered a luxury, but today with so much traffic and pollution, I'm thinking there might be a better way to bring fresh air in. I do plan to install A/C, but I don't like to run it all the time generally. I do like the idea of a filter at the intake at least, and a flap that could be closed in winter would help. Or, pulling air from the cowl might compare better with newer cars' ventilation systems. Interesting topic. Good luck.

Edited March 16, 2012 by alternativez

[5thhorsemann]

The driver's side of mine is stopped up with a rodent nest. I would suggest, and have seen, a screen over the entrance of them to prevent just that.

Bonzi Lon

Bonzi, I had the same problem on my 73. I taped a shop vac hose to the intake and surged the vac by opening and closing the interior controle. Worked like a champ.

[Bonzi Lon]

I don't have a shop vac, just a small one. I tried to push the hose in there but it was too large and the vacuum is a wimp. Then tried the air compressor hose with an open end, I think it got packed in there tighter. Then took the air hose to the inside, still couldn't get anything to come out. I will go to the local tire shop and borrow their 'bead blaster', an air tank for low profile tires, the valve dumps ALL the air in the tank at once. I'll connect a hose to it from the inside and blow it out the front.

I imagine a filter could be put on the front of the elbows, which could reduce the air flow. I will put 1/2" hail screen on mine. The only reason for the rodent nest was it sat in the back of the garage for 26 years, that was the only rodent damage, so I feel lucky.

alternativez: If you remove the elbows, it will cut off or greatly reduce the air flow, or just keep the vents closed.

Bonzi Lon

[John Coffey]

I just run the -10 oil cooler hoses through the front unibody ducting. Cleans up the engine compartment nicely.

[mgomez]

I need the cable to the vent that goes to the fender. Anyone have one? Like the idea of a cabin filter. mg