View Full Version : Vintage Air Gen IV- what about those cable driven fresh air vents?

09-30-2015, 10:14 PM
Spent alot of time installing this VA Gen 4 "servo actuated" system in my restomod 57 Nomad. The difference between earlier generation VA systems was that all "blend doors" in the evaporator unit were still cable activated. (old style steel cable in steel sheeth).
The Gen 4 system comes with the evaporator "blend doors" being servo driven (electric actuator motors atop the pivot point of the inner doors). These are controlled by wiring, and the VA's electronics control unit.


So I want to ADD servo actuated "fresh air" vents. I want to completely eliminate the old cable activated system. It's clunky, hard to route stiff cables, and generally leaks fresh air even when closed due to the antiquated felt design of the inner oval shaped doors.


On the passenger side of the fresh air ducting, the "tee" for feeding air to the (now eliminated) heater box was unnecessary, so I cut it out and will be welding the hole up.


Both sides (passenger and driver) have that same oval shaped inner door that leaks at high speeds, because the design is poor, and the air has no where to go when the door is closed. Both sides could stand to be improved so that when closed NO AIR passes thru to the inner cabin.

What I want to do is create a new "fresh air blend door" insert (to fit inside that old section with the oval door) with:
1. A solid, air tight Blend Door/housing.
2. That is opened or closed via servo actuator
3. and is controlled by adapting the Inside/Outside lever that sends the signal to the servo (ie the stock climate control levers on the dash, same way the other 3 levers now operate with the VA conversion switches mounted behind them)


To do all of this, I will need to design a new "blend door housing/insert" that:
1. fits/mounts into the existing (approx. 6" long x 5" diameter) driver/passenger horizontal section of the existing air ducting
2. contains an inner air-tight (when closed) blend door on a vertical "pivot" rod
3. includes a bypass outlet aiming the fresh air at the engine compartment (when the door is closed...because air will build up inner pressure that has no where to go at high speeds. Why not cool your engine compartment?)
4. contains a servo driven motor, over the pivot that can be attached to the vent ducting

Here's a pic of the servo's on the VA Gen 4 system...could use this style servo-actuators I suppose...


So what I envision is a sort of "insert" (injection molded) out of ABS plastic, that can be inserted/mounted into the existing air duct tube (once the old oval door and pivot is removed). An insert that contains a round blend door on a vertical pivot...with a sort of rubber edge so that it seals itself completely when closed. The piece could be "caulked" in once its securely mounted inside the existing duct tube, to keep air from going around it.


In the HVAC world, it would look kind of like this...


The challenge is the servo-wiring part.... The VA controller is not configured for these additional 2 servo motors, so there's no way to add this into it without knowing how the whole thing is built and programmed/configured. More than I'm cut out for...this is a product upgrade idea if VA were to take it on...(haven't bothered to approach them yet).

Wondering what you guys thing about my idea here?

60+ mph in 100 degree weather in SoCal with the AC on, the fresh air vents closed, and the car's still pumping hot air into the cabin from OLD INEFFECTIVE AIR DUCT/DOOR DESIGN...
Have been dealing with this in my 9 passenger wagon ever since I put a VA Gen 3 system in there...

Hammer away here. I'm all ears...

10-01-2015, 07:19 AM
I guess I'm not understanding what's wrong with the OEM design that allows air to get past the valve. Wouldn't it be easier to just fix the seals on it rather than to start all over and build a new part?

Are you wanting this to be just open or closed, or are you wanting a full range of operation? Using a servo is going to take some additional electronics and I'm not sure where you're going to get that off the shelf. There's probably something available if you look around. Another option would be to use a 12V gearmotor similar to an electric vent window motor or the motors on electric exhaust cutouts. It wouldn't provide any position feedback and you'd have to open and close it manually by holding the switch, or using an automatic window up/down controller. If it's just open and closed you want you could use a power door lock motor.

12-29-2015, 08:10 PM
Put this one on the back burner for a while, and now coming back to it.

Going to replace the seals and use the existing oval shaped damper doors.

Then going to mount up electric actuators (on-off action with a 3/4 inch throw, typically used for door locks). Found these online for $5 each.


Then going to wire up a switch behind the (dash mounted) lever activated fresh air vent controls, to power the actuators to open and close these vents.

Decided that all the mental effort for new damper door design was not worth it. But it seems like a natural Vintage Air upgrade for use in 57 Chevys... get rid of ALL the old cables coming thru the firewall...

Moving on with a simpler design.

02-02-2016, 08:40 AM
Fabbed up the fresh air ducts to work from new electric actuators.

Started with the passenger side, first removing the tee (formerly used with a stock firewall mounted heater box that was long since removed)

1. Cut the pivot rod

2. Drill out the spotwelds in the old cable sheath mount.

3. Remove the flapper assembly (slide it out) and then grind the spot welds that hold the pivot rod to the sheetmetal oval pieces.

Then separate the 2 pieces of sheetmetal flapper ovals, and remove the old felt seals.
Then clean em up, and reassemble the 2 pieces together with new felt seals.

02-02-2016, 08:46 AM
Then fabricate new pivot rods (3/16 rod that can be bent up in a vice).

Then assemble the rods into the oval flappers, within the vent tube (mock it up) and spot weld them back onto the oval flappers.

Then weld on nuts to the outside of the vent tube, for where the actuator will bolt into.

Then paint and assemble the unit.

5606 5607 5608 5609

Then mount the actuators and apply 12 volts to one lead, ground to the other and test it in the open position.
Then switch pos and neg and test it in the closed position.


Now I need to figure out what kind of a switch to get for installing behind the control arm that opens/closes the fresh air vent (on the lower dash). Something that works from a lever...

NO MORE CABLES coming thru the firewall...

02-02-2016, 09:58 AM
I'm surprised that 3/4" throw is enough for full travel.

02-02-2016, 02:27 PM
The oval flaps only need to travel about 30 degrees tops. From the closed position (against the inner tube) to "dead on straight" (parallel with the vent tube) really isn't that much travel. I messed with them for a while to locate the actuators to the right position so they would articulate as described.

02-02-2016, 07:00 PM
OK, I had assumed that the flap needed to travel a lot more than 30 degrees.

Nice addition to your car!