64roadster

I"m reassembling my '64 non-AC basket case / project car and have a question I could not answer using my AIM, NCRS Judging Guide, nor parts catalogs.

Q Is there supposed to be anything to seal the gap between the heater box and the defroster Y-duct?

I have a gap of ~ 1" that seems to make the defroster less effective than if it were sealed. Since the heater box and defroster duct are both fixed in position it would make sense to have a flexible material to form a seal.

ctjackster

the Y duct fits like crap and that's the way it is. I had the exact same reaction when I first reinstalled mine after returning my car to original, thought I had got it wrong.

Trophy Blue

My ducts have a putty like material around of all of duct connections. Maybe Bubba and his brother Cletis put it there? Who knows?

64roadster

Thanks, I may use some material to close the gap although I don't expect to need defrost when I'm driving the car.

I appreciate the quick responses.

Happy New Year

62Jeff

Someone, maybe JohnZ, recently posted that the fit is loose so as not to transmit noise from one part to another.

Jeff

MikeM

It's not designed a snug fit. A one inch gap is larger than anything I've seen. If yours really is an inch, I'd look for something bent or mis-located.

SPLITRAY

I just ran into the same thing. I'm going to refit and redrill to attach it and use foam as a sealer.

64roadster

That's a great idea Mike, I think I'll cut a piece of foam material to seal the gap.

Thanks to all.

65nassau

Gordon, we discussed this in a recent thread I have linked here ... you are definitely on the right track, though.

http://forums.corvetteforum.com/show...highlight=duct

Hope your car is coming along well, I can't wait to see it!

- Bob

JohnZ

It's designed with a gap on purpose (standard GM design practice) to isolate the defroster outlet duct from the heater box; if the two were connected together, the noise/vibration from the blower and heater box would be transmitted through the defroster outlet duct to the top of the main dash panel, which acts like a drumhead and amplifies the noise. Later cars used a foam donut seal to fill the gap to make the defroster more effective, but they were never attached together.

65nassau

That explains a lot, John.

With the other thread we had going on us Bubbas, (well mainly ME) were wondering how the NCRS guys do it....without using Duct Tape!

Is that foam seal still sold by anyone?

mudbone64

It is not my intention to hi-jack this thread, but I am also currently re-vamping my heater box (new core etc) and I have a question. Does anyone know about a "vacuum heater switch" supposedly located on the heater box? I've searched through my assembly manual and cannot find it. I just happened to see this switch in the Volunteer Vette catalogue and am wondering exactly where it is located on the heater box (part no. Volunteer Vette item no. HA49). Any help concerning this would be appreciated. And yes, my "Y" duct also has plenty of slop in the fit.

62Jeff

On my 65, a factory A/C car, the switch is mounted to the top of the heater box. Pulling the Hot/Cold **** on my A/C system opens this valve allowing more and more vacuum to reach the vacuum valve in front of the heater core that is in-line with the heater hoses. See the area in the orange circle below. Note, if the picture does not appear below, try accessing it directly at http://i1.tinypic.com/2v16cgm.jpg

mudbone64

Is the vacuum heater switch for AC cars only? My car does not have air and I don't recall seeing any mounting holes for the switch on the heater box.

62Jeff

Yes, as far as I know, only AC cars have it.

mudbone64

I appreciate the help.

JohnZ

There was never a foam seal used in production on midyears, but you can make one from foam you can get at Home Depot, Lowe's, etc.

64roadster

Thanks to everyone for the input.

Since I did not disassemble my project I have to learn about piece as I get it ready for installation. I suspected there may have been an abandoned seal of some sort. I still like the idea of making a part out of foam.

I'm about ready to install the radio side panels and the console. After which I will finish the rear carpet then install the steering wheel and seats.

My '64 is starting to look like a car.

spanishsilver

Here is my fix for that problem. I have a 77 and here are the before and after.
Thought I did something wrong until I got to this thread. Thanks Guys