First post! Newbie....67 cowl panel fix.

[robbz28]

Hello, my name is Rob, this is my first post on here, please don't pick on me about the Z28 in my screename...yes i have a camaro too and this is my screename for everything lol.
Anyway, i just purchased an original numbers matching 67 mustang coupe with 289, a/c, p/s. The only thing was it had been repainted a different color. I got the Marti report on it and done the rest of the research on her. On to why im on here, of course this car had the dreaded rusty cowl panel that I have been planning on fixing properly. The floor pans were in terrible shape, so i bought the left and right full pans and did that repair over the past couple of weeks, even managed to squeeze a new torque box in there. I have gutted the dash and can clearly see the rust around the fresh air vent on the drivers side from underneath. I know this cowl job is a pain, but a necessity. I thought about something that I hope someone out there has tried and can help me with. I am doing a restomod on this car, I dont care about concours correctness, i just want a sweet looking stang to cruise around in. The a/c in this car needs a complete overhaul...which will cost me about 1000 bucks.....soooo i thought about just buying a new aftermarket kit from custom auto air. From what I understand these kits don't need the cowl vent for their air supply, and the fresh air vent...well, if you have air, its not very critical. What i had in mind was to just eliminate the cowl vents completely, to cut out the louvers and dig all the trash out and do my best to kill all the rust i can from under the dash and from the top side through the vents, and then just patch up the vents and make the cowl smooth. I found a site where some guys do this regularly with mavericks....check it out and tell me if any of you think this is a good idea, or if any of you have done this.

CAMEO CLUB

Thanks for reading and I hope to get lots of good info from here in the future.

 

[6Stang7]

I'm fixing the cowl on my 67 as well, and I did think about shaving off the cowl vents. As you pointed out, the only issue with doing this is that your heater and a/c won't have anywhere to pull in fresh air. However, since you are getting a new a/c system that pulls air from somewhere else, there shouldn't be a problem shaving the cowl vents. My only question is if the heater will pull air from the a/c's new fresh air location? If so, then I think you're golden.

 

[robbz28]

According to their website this is an entire new unit, heating and cooling, they only use the cowl vent as a mounting point, so i hope to get a cool custom look and just eliminate the cowl problem completely, also if i just wanted to later i could fix it properly because of the new panels now available. Anyway, just hoping to find someone on here that has actually done this to get some pointers. Thanks for replying...

 

[68stang351]

Hmmmmm, I might go this route also on my 68. I don't drive it in the rain, or in the cold, I have no a/c or heater core and don't need defrost, so this is an option for me.

 

[2+2GT]

Interesting- If the AC unit does not use the fresh air of the cowl as a source, where does it get air?

 

[Red5oh]

It doesnt need fresh air... it takes the air from the interior of the car, which is eventually the best air to recirculate. It is cooler and that is what makes the air work to the lowest temp. If you only tried to cool 90+ degree air every time, it will not work that well. If you have it recirculating interior air, then the temp will eventually become very cold. This is what determins "max air" from "normal air"

Make sense?

 

[6Stang7]

You know, that reminds me of one night when I was driving home with a friend from a party. While on the way home I yawned, and he remarked that I must be tired. I told him I didn't feel tired, but just felt like yawning for some reason. He then remarked, "O well that's why, you don't have the fresh air vents open; you're running out of oxygen."

He usually doesn't think before he speaks.

 

[rebel65]

i donno, theres that old urban myth of don't leave pets or kids in the car with 'resirculate' on the ac or they will slowly run out of o2
*shrug*

 

[kilgorq]

02 Will eventually run out if you have a well sealed car and you plan on being in it for several hours.
The problem you will have not pulling in fresh air will not be with the AC but with the Defroster. Defrosters do not work well with recirculated air. I am not sure why but it was a huge problem on my truck when the air door stuck. I could not get the windows to defrost unless i cracked the window a little. Once I fixed the door the problem was gone.

 

[rebel65]

'frost' forms from the differential of temperature on each side of the glass. i think ; )
so i would think that outside air for that reason would be tons more efficient.

 

[6Stang7]

02 Will eventually run out if you have a well sealed car and you plan on being in it for several hours.

Well, cars are not that well sealed. Unless the car doesn't take on water when submerged, the refresh rate of O2 will outpace the depletion rate. When you inhale, you remove O2 from the volume of air that is made up of the inside of the car. The affect is that the inside of the car is at a lower pressure then the outside. As such, atmospheric pressure pushes new air inside the car so that equilibrium is reached.

'frost' forms from the differential of temperature on each side of the glass. i think ; )

Depends. The 'frost' is water, which came from the moister in the air. When air containing moister (water vapor) reach the dew point (which is a function of both temperature and pressure), the water vapor condenses into water. The defroster heats the water/reduces the pressure that the water is under (the pressure of a fluid, like air, goes down as the speed of the fluid goes up) until the water reach the evaporation point, at which point the water becomes water vapor and is distributed back into the air.

 

[rebel65]

so 'frost' on the window has nothing to do with it being warmer on one side? : )

 

[6Stang7]

so 'frost' on the window has nothing to do with it being warmer on one side? : )

Not specifically; you could have the entire windshield be the same temperature and it still have fog on it (one side or both). If the air has moister in it, and the glass is at the dew point temperature for the given atmospheric pressure, then your windows will fog. The fog is tiny drops of water that came out of the air. It's exactly like when you get condensation on a cold beer bottle sitting on the table.

 

[rebel65]

i shoulda taken physics : ).

 

[robbz28]

Wow...didn't realize i was amongst a pack of geniuses, lol, i just want to know yes or no, i didnt need the theory of relativity explained to me as to "why". Anyway, all jokes aside, my car is just going to be a weekend cruiser, and parked inside a garage (usually don't have the fogging problems when your car is kept inside, not where I live anyway) and frost is nearly a non issue here in Louisiana...maybe one or two weeks out of the year you may have to deal with it, then again, parked inside....soooo i think i am going to attempt this fix, i will document it really well and try to cook up a "how to" and just let you guys know what the outcome and drawbacks are if any.

One more thing I was thinking about last night....couldn't you technically turn any a/c into a recirculating one (provided you had all outside air cut off) because of the fresh air vent on the driver side? If it was open then your a/c could just use the cowl as a duct to pull the air accross from the driver side and cool the air back into the cabin? Just a thought.

 

[2+2GT]

Hmmmmm, I might go this route also on my 68. I don't drive it in the rain, or in the cold, I have no a/c or heater core and don't need defrost, so this is an option for me.

Good luck passing technical inspection in most states without functional windshield defog.

One other consideration is the cowl is not just decoration, it's a large torque box joining the left and right side of the car together. If it's rotten, the car is weakened.

 

[robbz28]

The defroster will work...all it does is pass heated air to the windshield....it might not work like its supposed to, but what are they going to do? Tell me to come by when its frosty to test it? Plus all they really care about around here is insurance, blinkers, lights, horn and sometimes wipers.
True that the cowl is a structural component, but my cowl isnt just rotted to pieces, it just around the "hats", but i plan on reaching under the dash and just plugging those bad boys up with a fresh piece of sheetmetal, plus i added a passenger torque box and plan on putting frame connectors under the car, so that addresses that issue...
i really appreciate all the feedback guys, and giving me things to think about, but I have all but made my mind up to do this. the benefits still seem to outweigh the drawbacks, plus it won't cost me anything (except for a cheap piece of sheet metal and some time). So if I dont like it, or screw it up, the worst i have to do is go back and just fix the cowl properly.

 

[rebel65]

as someone said earlier in another thread as there are about 5 going on about cowls atm. the cowl drain vents or whatever they are called that go into the fenders will draw air from the outside if the cowl vents on top are obstructed somehow. so.. guess it's kind of a moot point.