C2 A/C Side (Ball) Ducts

[Peter L.]

I was told by someone at Vintage Air that original ball/side ducts had a hole

(approx 3/4")

about midway to the ball drilled into them, with a plastic movable cover, so that during the summer, cold air could be directed to your lower legs and feet. I have a 63, that I added Vintage Air to, and while it does a good job of upper and mid body cooling, your feet begin to roast after 20 minutes, once the engine heat flows thru the firewall. When I restored the car, I added a thick heat shield material under the rug, that goes all the way up the firwall, and we still feel the heat. Is what the Vintage Air tech told me about a hole in the duct to direct cold air to your feet true? Vintage Air tech told they used to have that feature on their ducts, but stopped doing it after a few years.

[Harry S.]

Re: C2 A/C Side (Ball) Ducts

Yes, look at the picture of the bottom..... https://www.ebay.com/itm/63-67-Corve...EAAOSwMftezCzX

[Peter L.]

Re: C2 A/C Side (Ball) Ducts

Well butter my butt and call me a biscuit! Thanks so much for the answer and photo reference. No one in my NCRS chapter ever said anything about that when I complained about the heat. And I've been complaining for the last 5 years! Much thanks agin. I will drill the hole in the next day or two, and let you know how it works. The photo also shows a knob that looks like it can limit flow of air to the ball outlet, forcing more air thru the duct bottom hole. Is that it's purpose?

[Peter L.]

Re: C2 A/C Side (Ball) Ducts

Harry,
I just drilled a 1/2" hole in each duct, and then taped off two of the three slots in each ball, and it still doesn't seem like enough air is coming out of the holes to make that much difference. It's hard to see scale in the photos, and if I go larger, and its turns out to be too much, I guess I could always tape over part of the holes with black duct tape. Any thouhgts on exactly what the size of the holes actually is?
Thanks,
Pete

[Tom E.]

Re: C2 A/C Side (Ball) Ducts

Peter,
Air flowing through a duct will not exit a hole drilled in the duct wall with any reasonable amount of pressure unless you have a defuser or some mechanical means of redirecting the air. If the duct is capped or has a restriction on the outlet to increase duct pressure the air will exit the holes relative to their size. On an automotive a/c duct the ends are open unless you close of the vent so it is basically an unpressurized air duct.

Tom

[Harry S.]

Re: C2 A/C Side (Ball) Ducts

Well butter my butt and call me a biscuit! Thanks so much for the answer and photo reference. No one in my NCRS chapter ever said anything about that when I complained about the heat. And I've been complaining for the last 5 years! Much thanks agin. I will drill the hole in the next day or two, and let you know how it works. The photo also shows a knob that looks like it can limit flow of air to the ball outlet, forcing more air thru the duct bottom hole. Is that it's purpose?

If you close the duct more air will be directed down if the hole is exposed. Otherwise it limits the duct flow through the ball. The hole is one inch. The picture is from my 63.

IMG_1069.jpg

[Leif A.]

Re: C2 A/C Side (Ball) Ducts

I must admit I never noticed them on my '67 but sure enough they are there on both the driver's and passenger side.

[Peter L.]

Re: C2 A/C Side (Ball) Ducts

Guys,
Thanks for the posts and info. I have a question. On Harry's post, he has a link to an ebay sale with pic's that show a bow tie shaped knob sticking out the front directly at the car occupants. Is this an internal baffle inside the duct used to reduce air flow out the balls, and increase air flow out the hole in the bottom of the duct? Possibly a way to balance the air flow for different outside temps?

[James W.]

[Peter L.]

Re: C2 A/C Side (Ball) Ducts

Guys,
Thanks for all your help. I now have cool air directed at our feet for those hot summer drives. I really appreciate the help.