Smooth Cowl - Who Wants One?

[5150]

I'd be interested too, don't care what it's made of just needs to be shaved all the way

[cameeks]

Originally Posted by Robznob11

the cowl bassicly just delivers the air to you kick panel vents, the heater box contains the core under the hood and then passes through the fire wall and connects to a vent system that has hoses that to to the defroster and sends heat out under the dash.

With the aftermarket A/C systems this is correct but with the factory system (A/C and Heating) you have inside air and outside air. The outside air comes from the cowling area and is the main setting for most of the newer cars for defrost.

[cbwabbit]

I'll take one with no wiper holes

[matt dillon]

I was the purchaser of the first smooth cowl from the ebay seller. I am very pleased with the product. I am placing vintage air and heat into my project so the vents would not matter. The product is more than I expected, needs minimal work done to it for painting. The seller packaged the item very carefully. I wish more companies would package a product like the seller did. The continued communication that I have received from the seller has been great. If I need more of these I will definitely purchase through him. I have been looking for one of these for the past year and finally found one that I approve of. Would highly recommend the seller of this item.

[LUV2XCLR8]

Good to hear Matt, he is building me one right now

[Classic Heartbeat]

For those of you that think that your non A/C truck draws air from anywhere but the cowl should go look at your truck.
The non A/C trucks get the air for the heater from the cowl vent only. The A/C trucks have the ability to draw air from the cab by closing the flap in the cowl, and opening the kick panel vent on the passenger side. (Does it with Vacuum diaphragms.) If you close off the outside air source, something else has to open to draw the air from. (For A/C trucks it has to be the cab.) The reason the A/C trucks have this ability is because, the A/C system can only has the ability to cool the air about 12 degrees below the ambient temperature. By drawing recirculated air from the cab, each time the air passes through the coils it cools another 12 degrees. That is how the A/C works. If it didn't have that capability then if the outside air temp was 100 degrees, then the coolest that the A/C could get it would be about 88 degrees and that is with everything working perfectly. You do not have that problem when it comes to heating the air, because air heats faster and easier than it cools.
Now!! If you install a non vented cowl panel, where will your heater draw it's air from? Answer: Your engine compartment!! Through any place that it leaks air. Nice oily, smokey, and toxic air..... MMMMMMMMM!! So unless you somehow create a different place for the heater to draw it's air from I would reconsider whether or not you really want this modification.
I am not trying to spoil anyone's day, or tell you to or not to buy, not buy, or make one of these panels for yourself. Just trying to inform you... Why you ask? Because that's what I do...lol JK... Anyway here is a picture of where your heater fan seals to the firewall. You can clearly see that it draws air from inside the cowl. WES

[eightbanger]

Thank God for people who know what they are talking about.

Why not shave the headlights the taillights the grill and on and on

[Mondo]

Anymore word on these? I want one

[GMC Jim]

The temperature of the discharge air into the cab is controlled primarily by the temperature of the outside air entering the condenser (mounted in front of the radiator). Referring to the 1971 Chevrolet Truck Service Manual, Heater and Air Conditioning system; page 1A-17:- With the temperature of the air entering the condenser of 100 degrees, engine RPM @ 2000 and high blower speed, the discharge temperature at the right hand outlet should be 41-44 degrees. The specs do call for setting the upper lever for inside air. The inside air setting does supply a faster cooldown of the air for test purposes. If a thermometer was inserted between the fins of the evaporator (located inside cab heater core and distributor assembly box); then the temperature or the air source would be immaterial. I have found that using outside air as a source; the outlet discharge temperature will be about 50 degrees.
Over 15 years ago; I modified my system as follows:- removed vacuum line and sealed the right kick panel inlet; removed vacuum line and the flapper valve from cowl plenum. This enables outside air only to the system. Installed a switch on the dash lip directly under the fan switch to control the compressor. Repaired and checked for proper operation; temperature, air cond/heater floor and the defroster flapper doors. Also replaced the water valve and checked for proper vacuum operation.
This modification enables complete control of the heater/airconditioning system. I find it quite useful in this damp Oregon climate to be able to use heated /air conditioned outside air for rapid defrost operation. Heated and/or airconditioned air can be blended and directed to desired outlets.
I find that outside air intake to be a must if the occupants are smokers!!!!

[see ten]

Valid points on the fresh air. However guys running Vintage Air systems wont have that problem. Also guys like 5150 who are building a roadster with no heat or air are obviously not going to have a problem. So why not shave the headlights and taillights? Because we are required by law to have them. There is no law that says we can't customize these rigs by running a shaved cowl and cutting off the supply of fresh air ,IF we're using a factory heat/AC system.

[5150]

well said mate

same here, if it's steel you got a deal but not crazy on fiberglass. does anyone offer this in steel or do i need to smooth one out myself?

[tdave00]

What's the weight difference between the steel cowl and the fibergalss one? It's can't be much.

[Ks4x4]

Earlier on someone stated that the kick panel vents draw their air from the cowl vents right? If you close the cowl vent completely then wouldn't the heater just draw it's air intake from the kick panel vents now?

[Liz]

moved to the message board since this has become an interesting discussion and its not a for sale ad.

[shifty]

Originally Posted by Ks4x4

Earlier on someone stated that the kick panel vents draw their air from the cowl vents right? If you close the cowl vent completely then wouldn't the heater just draw it's air intake from the kick panel vents now?

Only if the kickpanels are open all the time. If the kick panels are closed, it will be sucking on a vacuum and pull air from anywhere it can - including sucking carbon-monoxide laced air through the windshield washer holes and any other crack it can find.

[Scott Webster]

Then we could just make the kick panels permanantly open maybe with a screen similar to a speaker?

[shifty]

Or just remove the door, but you still need to consider the fact that you will NEVER be pulling massive amounts of fresh air, so by pulling air from the cab and recirculating it through the cowl area, which has openings to the engine compartment, the longer you stay in the truck, the more exhaust you're going to introduce into your air supply inside the cab. If you had a window open all the time, this probably wouldn't be a problem, but on long road trips with the windows rolled up, I think you're asking for trouble. Any carbon monoxide intake is bad. Constantly trickling more and more CO into your air stream is really, really bad.

[Robznob11]

yep they are right it does pull air from that round hole, i guess mine has been smoothed so long that i forgot about haveing it, id just make it suck from inside the cab my self, sorry about the miss info i done away with my whole factory set up years ago and smoothed all the holes guss you forget what was there when you cant see it any more, my .02 is that that whole cowl is a sucky system that causes 95% of these trucks to be cancer victims. thats why i did away with it

[Rollie396]

So why couldn't some ambitious soul shave the cowl and make a new fresh air intake.Maybe cut a hole in the air box behind the fender, and fab up some sort of duct that will lead up to, and pass through or maybe under the core support.Then make some sort of cool screened scoop hidden behind the grill or a real low profile one just under the bumper?Sounds like a ton of work...

[Ks4x4]

Originally Posted by shifty

Only if the kickpanels are open all the time. If the kick panels are closed, it will be sucking on a vacuum and pull air from anywhere it can - including sucking carbon-monoxide laced air through the windshield washer holes and any other crack it can find.

Mine don't seal very good anyway, lol. I like the idea of removing the doors and making a screen/cover for the hole.

Originally Posted by shifty

Or just remove the door, but you still need to consider the fact that you will NEVER be pulling massive amounts of fresh air, so by pulling air from the cab and recirculating it through the cowl area, which has openings to the engine compartment, the longer you stay in the truck, the more exhaust you're going to introduce into your air supply inside the cab. If you had a window open all the time, this probably wouldn't be a problem, but on long road trips with the windows rolled up, I think you're asking for trouble. Any carbon monoxide intake is bad. Constantly trickling more and more CO into your air stream is really, really bad.

How would this be any different than driving without the heat on and the windows up? It's still the same air. I understand what you are saying but I think you're going a little overboard with your above statement. You make it sound like our cabs have ductwork directly attached to the exhaust.

[shifty]

Originally Posted by Ks4x4

How would this be any different than driving without the heat on and the windows up? It's still the same air. I understand what you are saying but I think you're going a little overboard with your above statement. You make it sound like our cabs have ductwork directly attached to the exhaust.

If you shaved your cowl and are running stock heat, it is no different. If you're running a normal cowl, you won't have a vacuum under the cowl area, so you won't be pulling exhaust from the engine bay.

Hey, if inhaling CO is cool with you, fine. I'm just tossing a worst-case scenario out there.

It's bad enough I gotta worry about lung cancer and countless other crap from pollution out there. Last thing I want to do is breath in exhaust and smells from my engine bay all day long. I guess some people could be into that....

My whole reason for posting that is to get people to actually think about what they're doing, rather than just blindly hacking stuff because "it looks cool". I don't want one of you guys passing out at the wheel from CO poisoning and plowing into my family or friends.

[shifty]

Originally Posted by Rollie396

So why couldn't some ambitious soul shave the cowl and make a new fresh air intake.Maybe cut a hole in the air box behind the fender, and fab up some sort of duct that will lead up to, and pass through or maybe under the core support.Then make some sort of cool screened scoop hidden behind the grill or a real low profile one just under the bumper?Sounds like a ton of work...

I think the better way to handle the situation would be to filter the incoming air somehow with something that will actually take care of CO particulate. You'd probably want this to go on the blower side (before the air reaches you).

[piecesparts]

I am interested in one that is steel.