Getting fresh air in with a Vintage Air set up

[PatO]

When I was restoring my 1972 Challenger I was faced with a choice between my original air conditioner set up or the vintage air unit.  The only original components still with the car were the heater/air conditioning box and defrost vent in the car. Nothing was left in the engine compartment, the wiring was gone and all the controls were trashed.  Actual air conditioning wasn't that important to me but the dash had the vents in it. I decided to go with the Vintage Air Unit, but just the interior side. While deciding I discovered that there was no fresh air intake incorporated to the new setup - just a plug to seal the original fresh air inlet on the passenger side.

I had the various holes that I no longer needed in the firewall all welded closed. I installed the interior portion of the vintage air unit just to circulate air in the car and have the defrost available should I need it. I did not purchase or install any of the engine bay components - compressor, dryer etc.

That worked up to a point but having to open the window frequently was a pain, especially at highway speeds. I even started to consider refurbishing the original unit but gave up on that approach.

So after much thought I decided to see if I could figure out a way to get some fresh air into the car. Took a bit of McGivvering but I came up with a setup that works for me so far.

First I found some black PVC fittings that would suit my purpose. Searching over the net and on Amazon I found some 4" black PVC fittings that are used for dust collection systems in wood shops. They are pretty sturdy and not very expensive. I purchased the mounting flange with a 4" inlet, a 4" slip on adapter, a small sheet of 1/8" PVC sheet and a 3/16" brass rod.

Here is a pictures of what I purchased for my project. To the left is the vent plug from vintage air.

[PatO]

I cut out 2 round pieces from the plastic sheet and glued them together and then sanded the edges to make a tight fit in the tube. A sort of butterfly valve so to speak. I glued the slip on adapter to the flange, squared the flange off a bit, then scribed a 4" cut out in the vintage air plug, also PVC. I also made some measurements and bent, cut and drilled some holes in the brass rod and made a very basic bell crank.  I also found a universal fit choke cable to use to open and close the valve.

[PatO]

So, some more careful measurements to drill the holes for the bell crank and keep the butterfly valve centered in the bore I was able to assemble the valve and attache the assemble to the vintage air plug.

[anlauto]

Interesting idea, I suppose you could cut the steel and install something similar on the drivers side too 

...or you could just roll down the window 

[PatO]

At this point I mounted the assembly back into the factory fresh air inlet in the cowl and crudely mounted the choke cable so I could open and close the valve in the new air inlet. The choke cable is temporary just to see if I like how this works. More pictures below.

So, 1 test drive today to see how this worked put for me.  It's been pretty cool lately in Colorado so I would be able to tell how much air was entering the car.  After a few miles I was warm in the car so I opened the valve and could clearly feel the air coming in below the dash. Definitely noticeable, and at highway speed I needed to close the valve slightly.

The air outlet is only a few inches from the vintage air's fan/intake so turning on the fan drew the air in from the new vent and readily pushed it through the dash vents and defrost vents. I was pretty happy with how this turned out.

At this point I am going to live with it for a few months and then go a little further. I'll probably need to take it out and redo a couple of things.  My brother is an electrical engineer and hobbyist and he is going to help me with installing a stepper motor on the air valve assembly and a small rotary control in or under the dash so I can control the valve electronically instead of using the choke cable.   

[anlauto]

Could add an elbow to it as well....Or a future version you could use a 3" electric exhaust cutout with a remote 

[PatO]

I have thought about an elbow.  Also considering using some sheet plastic to construct a partial box or shroud right up to the intake.