Manifold heat control valve replacement?

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Doug.S

Doug.S

1964 Dart More Door
Joined
Jan 21, 2018
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Location
Saylorsburg, PA
Just brought home my new daily driver. 1964 Dart 170 4 door. Its equipped with the 170 /6 and push button auto trans. I pulled the intake and exhaust manifolds to fix an a exhaust leak. I noticed the rotating wheel and spring are not on the exhaust manifold. After I have the manifolds off and separated, I notice the heat control valve is completely stuck and wont move. It is in the vertical position, so exhaust gas can move upward and touch the bottom of the intake, or travel down and out the pipe. I want to replace this mechanism but cant locate parts and or instructions. I am under the impression I will need an exhaust manifold? Any thoughts or recommendations will be greatly appreciated.
Doug
 
New manifolds are available on eBay and other sources and are not that expensive or too bad for being Chinese made.
 
You might be able to free up the valve so that it works. It's tempting to grab whatever penetrant you happen to have around, but do yourself a large favour and buy a can of this. I don't know what the heck is in it—it smells way different than any other penetrant, and it works differently too, including standing you your best chance of freeing up a stuck manifold heat control valve, which is what it was originally formulated to do.

Don't bypass or otherwise disable the valve; it serves a very useful purpose no matter where you live (hot, cold, whatever). This 1935 Jam Handy cartoon, "Down the Gasoline Trail", would be a real trip to watch even if it didn't contain a sequence specifically explaining why (at 5:37).

There used to be manifold heat control valve repair kits containing all the parts needed to rebuild the valve. They have been unavailable for years now, and NOS units are expensive enough that it's better to just buy a complete new manifold.

New manifolds are available, as 65 Dartman says. Quality varies quite a bit, so you have to shop carefully. Info on picking a good one and the necessary carb choke adaptation is here.

It is very much worth your while to get the good gaskets for the manifolds-to-head and intake-to-exhaust junctions, and while you're at it, pay attention to the mounting hardware
 
slantsixdan said:
You might be able to free up the valve so that it works. It's tempting to grab whatever penetrant you happen to have around, but do yourself a large favour and buy a can of this. I don't know what the heck is in it—it smells way different than any other penetrant, and it works differently too, including standing you your best chance of freeing up a stuck manifold heat control valve, which is what it was originally formulated to do.

Don't bypass or otherwise disable the valve; it serves a very useful purpose no matter where you live (hot, cold, whatever). This 1935 Jam Handy cartoon, "Down the Gasoline Trail", would be a real trip to watch even if it didn't contain a sequence specifically explaining why (at 5:37).

There used to be manifold heat control valve repair kits containing all the parts needed to rebuild the valve. They have been unavailable for years now, and NOS units are expensive enough that it's better to just buy a complete new manifold.

New manifolds are available, as 65 Dartman says. Quality varies quite a bit, so you have to shop carefully. Info on picking a good one and the necessary carb choke adaptation is here.

It is very much worth your while to get the good gaskets for the manifolds-to-head and intake-to-exhaust junctions, and while you're at it, pay attention to the mounting hardware
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If that mopar rust penetrant is kinda blackish, maybe it is the old mopar heater control solvent. That stuff was awesome. I bought about a dozen cans twenty years ago, because it was the best.
 
Thanks for the replies! I didn’t think it was fixable, but good to confirm it with the experts.
Slantsixdan, I ordered the Dorman and the special nuts from MCMaster Carr. I can’t get the link to work for the electric choke. Do you know a part name and number so I can find one and get it ordered up? Thank you for sharing your time and knowledge. It is truly appreciated.
Doug
 
Yes, the linked penetrant is the current labelling of the same old heat control valve solvent. Weird greyish-black colour, weird indescribable smell.

Which link isn't working for the electric choke? I just tried the links I posted and they all seem to work; electric choke info is here. You'll need a № 1231 kit.
 
Doug,

I recently bought a new Dorman exhaust manifold because the previous owner of my car had welded the 'heat box' shut. Don't have any dilutions that the new manifold is going to function properly without significant re-work. I had to machine my manifold to bring the ports into the same plane. I also had to modify the exhaust box flap very significantly to make it even move freely! In my experience you have to assume that the 'new' manifold is just a starting point... you will need to rebuild it before actually using it. So if the old manifold is not cracked, I would advise fixing it. Or, perhaps, you can find a NOS manifold.
 
J Glenn said:
I recently bought a new Dorman exhaust manifold (…) Don't have any dilutions that the new manifold is going to function properly without significant re-work. I had to machine my manifold to bring the ports into the same plane. I also had to modify the exhaust box flap very significantly to make it even move freely!
Click to expand...

This what you describe is not even close to normal. You got a severely defective manifold—should've returned it in exchange for another. Most people who buy the dorman manifold have no trouble bolting it on and going on with their lives.
 
slantsixdan said:
Yes, the linked penetrant is the current labelling of the same old heat control valve solvent. Weird greyish-black colour, weird indescribable smell.

Which link isn't working for the electric choke? I just tried the links I posted and they all seem to work; electric choke info is here. You'll need a № 1231 kit.
Click to expand...
good to know it is still available, it's the best I've ever used. One cautionary note, if you use it while on your back underneath your car, you would be wise to wear eye protection. The little capillary straw on the nozzle caught on something and it flicked a drop of that stuff into my eye. It burned like you wouldn't believe!!
 
I have thought of trying fireplace window cleaner (Ace Hardware, hand-spray) since it dissolves all kinds of hydrocarbon build-up. I think ammonia is the main ingredient.
 
I wanted to follow up this thread by saying I received the new Dorman exhaust manifold yesterday. I am pretty impressed with the quality. Looks to be well cast, and all moving pieces of manifold heat control valve are free and move easily. It fits on the car well (dry fit - not ready to install) and comes with a pretty impressive assortment of mounting hardware. Brass washers for the two outter most mounting holes, along with the acorn shaped lock nuts by the way. All the triangle or butterfly washers are there and the regular cast iron round washers are there too. Comes with intake and exhaust manifold gasket, intake to exhaust gasket, and exhaust manifold to exhaust pipe gasket too. I feel like the Dorman was absolutely worth the money. Thank you everyone for your help and suggestions. By the way I bought the Mopar rust penetrate to keep this working well into the future.
 
Search for the article on slantsix.org showing how to install the manifolds. The triangle washers are oriented opposite to what most people might think. If you don't assemble correctly, the exhaust manifold can later crack.
 
BillGrissom said:
I have thought of trying fireplace window cleaner (Ace Hardware, hand-spray) since it dissolves all kinds of hydrocarbon build-up. I think ammonia is the main ingredient.
Click to expand...

I've seen references to the Mopar stuff since i started reading FSM's in the 60's but never had any to try. Having said that I'd imagine it is MORE than just a rust penetrant. If I was going to spec something like that, I'd probably want a penetrant as a carrier but then as it evaporated or otherwise went away, I'd want lubricant left behind to lubricate the shaft and related parts. I'm thinking a graphite substance.

I'll have to get some for my 64 slanty as it has the heat riser in place and it works! My 68 is a small block with headers and I blocked the crossover in the manifold so It's a little cold blooded until it warms up. Makes the cam sound bigger
 
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