Heater Box Design - Lame?

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Lord Sparky

Lord Sparky

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I recently rebuilt my 1969 Dodge Dart non-AC heater box. What fun! I always thought a valve shut off the hot engine water coming through the heater hoses, through the firewall, and into the heater core. I learned there is no shutoff. Therefore, the interior of the car is being heated full time (the interior heater box is made of thin uninsulated fiberglass, 3 flaps keep most of the hot air from exiting the heater and defrosted ducts), even in summer. Today, I measured the exterior of the box to be 120 degrees, probably goes up to 180. Hot inside the car, even with the windows open. Am I crazy, or is the heater box design lame? Has anyone ever installed a shutoff valve in the heater hose for summer driving? The heater core probably does help cool down the engine somewhat. Would a heater hose shutoff valve impact engine cooling? I know this is 50+ year old technology, but WTH?
 
Pretty easy to add a valve. You want to know just how tough it was "in the old days?"

I am old enough to remember when Dad did NOT run antifreeze all year round, in ANYTHING. There was a pecking order for it, too. The stuff that came out of the "best" car went into the second vehicle or the tractor

Also I used to have a stack of Ford dealer "propaganda" magazines. These were small thin magazines distributed to the dealers. They may have been "Ford Times" I don't recall.

I remember one article from the mid 30's about how "Dealerships can make extra money by servicing cooling systems spring and fall, and draining and replacing antifreeze AND REMOVING AND INDEXING CAR HEATERS UNTIL NEXT FALL

I am old enough to remember riding in two different Model A's Dad had. One was a pickup made into flatbed (nice little truck!!) and the other a dump. The dump had NOTHING for a heater, and those cabs were DRAFTY!!! The flatbed had an accessory 3rd party deal, a trumped like device, the fan blew air into the "big end" and it fit around the exhaust and "hopefully" piped some warm air into the cab

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My '72 has a valve for the engine coolant to the core, and I seem to remember several at the salvage yards having them. Mine is an AC car, if that matters?

I seem to remember from my AC classes that some systems cool the air to get the moisture out (condensation on the evaporator?), then heat it, so maybe there's a reason the heat is on all the time?
 
Lord Sparky said:
I recently rebuilt my 1969 Dodge Dart non-AC heater box. What fun! I always thought a valve shut off the hot engine water coming through the heater hoses, through the firewall, and into the heater core. I learned there is no shutoff. Therefore, the interior of the car is being heated full time (the interior heater box is made of thin uninsulated fiberglass, 3 flaps keep most of the hot air from exiting the heater and defrosted ducts), even in summer. Today, I measured the exterior of the box to be 120 degrees, probably goes up to 180. Hot inside the car, even with the windows open. Am I crazy, or is the heater box design lame? Has anyone ever installed a shutoff valve in the heater hose for summer driving? The heater core probably does help cool down the engine somewhat. Would a heater hose shutoff valve impact engine cooling? I know this is 50+ year old technology, but WTH?
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I added a simple shut off valve in the heater hose from the water pump on my 340 set up in my 67 Barracuda and it did make a slight difference on the passenger side. I never did measure the difference with my IRF gun but you can feel it if you are the passenger.
 
jos51700 said:
My '72 has a valve for the engine coolant to the core, and I seem to remember several at the salvage yards having them. Mine is an AC car, if that matters?

I seem to remember from my AC classes that some systems cool the air to get the moisture out (condensation on the evaporator?), then heat it, so maybe there's a reason the heat is on all the time?
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YES A/C cars had a valve
 
You can keep it simple and add a valve and hook vac. at your Intake manifold during the cold season. Unplug and cap during the summer.
 
70s dodge pickups used a cable operated valve. Get one of those, mount it inline and install a cable.

Heres 2 nice retrofits for that. Cable and electric

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Just mount a valve in the hose coming from the water pump.
 
Why not close the blend door when you aren't needing heat???
 
Lord Sparky said:
....The heater core probably does help cool down the engine somewhat.....
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Not really sure about it helping the cooling much at all if it doesn't have air blowing through it to transfer heat out to the interior. Once the air in the closed box is heated what more can it do to cool?
If the box temp is not wanted inside, slap a valve on it and stop the flow. I doubt you'll see over heat issues.


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Or this if you dont want a cable to open and close it. Nicer looking than a plumbing ball valve. Open it up for winter driving.

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Thing was to open the vent windows and dog boxes under the dash, actually the non ac cars were quite survivable in the summer with all that air flow...of course I was younger:)
 
Dartswinger70 said:
Thing was to open the vent windows and dog boxes under the dash, actually the non ac cars were quite survivable in the summer with all that air flow...of course I was younger:)
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It's still a ***** in Georgia even with the air box doors open. Just a bunch of hot air. I may get one of them low profile valves and see if it'll help. Caint hurt.
 
RustyRatRod said:
It's still a ***** in Georgia even with the air box doors open. Just a bunch of hot air. I may get one of them low profile valves and see if it'll help. Caint hurt.
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Like said I was younger. The heat seems worse here in Pa than it used to be but I am older :) Funny re enr story I reached out to some lifeling firends said "i am having a bbq first weekend in august..." my one whiney friend said "nothing like August heat..." I said "Ill have up sun tents and it wasn't that bad last year it was 88...plus the AC will be on in the house..." yeah he wont show up :)
 
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I love cars with real vents and "wing wings." I have never gotten used to those that dont. Only thing saves is AC. Hell up in these parts we never had an AC car until after I got out of the Navy in 74
 
My ragtop is Black on Black on Black ! When I move to NC. in a couple if years I'm screwed. Might look for a 68 A/C set up .
 
What does the temp slider do on the OP's car?

Been a while since I had an A, but all my B's have that slider control a valve.
 
Yeah there is a foam seal on the blend door...I rebuilt my heater box a few years back
 
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My 340 had a shut off plumbed in on top of the water pump (cast iron style drivers outlet) I've switched it to a passenger outlet aluminum pump so I'm looking for a valve that will look "clean and simple" when installed. Might even leave the heater box out for the summer.

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