Manifold heat control valve.

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circlepilot

circlepilot

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Help! I'm having a senior moment. The manifold heat control valve on my "restoration project," (65 Barracuda, Super 225) was found to be seized, further inspection showed that it had, at sometime broke loose from its shaft. I took the whole thing apart, reworked the shaft, (drilled to accommodate screw to hold the valve) cleaned the valve, installed some bushings etc. When I went to reassemble the valve, I've decided that I'm not sure I have the valve installed right, I know the shaft is installed correctly. I've checked my manual, but the position of the valve is not very clear. The picture is how I've installed the valve with the "thermostat spring" in its "loaded" condition.
Norm
Manifold valve1.JPG
Manifold valve.JPG
Manifold valve.JPG
 
No expert but that looks right to me based on our current project......when the spring heats up the flapper should direct the exhaust flowdown and out.....cold, its "vertical", directing exhaust up into the hot box.

did you replace your spring or refurbish what you have? Ours broke and couldnt find the replacment kit anywhere for less than a couple hundred bucks so I just bought a Dorman manifold .
 
shadango said:
No expert but that looks right to me based on our current project......when the spring heats up the flapper should direct the exhaust flowdown and out.....cold, its "vertical", directing exhaust up into the hot box.

did you replace your spring or refurbish what you have? Ours broke and couldnt find the replacment kit anywhere for less than a couple hundred bucks so I just bought a Dorman manifold .
Click to expand...

I'm reworking mine...although I may do what you did and replace it. Y
heat riser 1.jpg
ou said "vertical when cold." I'll have to check that out as mine is "closed in the cold position. I may have the valve in right, but the spring loaded wrong. The other concern that I had was the manual talking about a counter weight. What is being call a counter weight on mine is a "lever" made from (what looks like) sheet steel. (see picture) There is nothing that resembles a weight. It does look like the same thing in the manual though??
Norm
 
There were 2 types of counter-weights. My 1964 slant and 1965 273 have round weights. My 1969 slant had the sheet-metal weight you show. I thought it was a year thing, but if you have the 1965 manual, perhaps slants got the sheet-metal then (I'll check my manual at home). Seems to me the round weights are a better design. Long ago, in my 69 slant it was rusted stuck and I recall the innards were mostly gone, so I installed stainless bolts & nuts in the holes. Didn't make winter starts any different in Atlanta.

I infer that a heat riser isn't needed w/ MPFI, which I plan someday for my slant. That is because I see no such provision in my newer Mopar engines (2.4L, 3.8L), nor in a Magnum V-8 intake I have. I think its main purpose was to avoid icing under the carburetor in the winter, though might have helped idling in winter after 30 sec running (time to heatup exhaust).

Before re-installing, be sure to read the excellent post at www.slantsix.org on installing the manifolds. The triangle and cone washers install the opposite of intuition, and if you do it wrong the exhaust can later crack. Best to coat the inside clamping bolt w/ anti-sieze since so many snap off there when removing. I used stainless bolts, but grade 8 might better (Ace has nice selection).
 
No, sir, that is not correct. With the spring in its loaded condition (shaft rotated clockwise as viewed from the front) the flap should be "standing up". When you rotate the shaft counterclockwise (viewed from the front) the top of the flap should move to the left until it deflects all the exhaust down and away from the intake.

It is very much worth your while to get the good gaskets for the manifolds-to-head and intake-to-exhaust junctions.
 
slantsixdan said:
No, sir, that is not correct. With the spring in its loaded condition (shaft rotated clockwise as viewed from the front) the flap should be "standing up". When you rotate the shaft counterclockwise (viewed from the front) the top of the flap should move to the left until it deflects all the exhaust down and away from the intake.

It is very much worth your while to get the good gaskets for the manifolds-to-head and intake-to-exhaust junctions.
Click to expand...

Thanks Dan, I will correct it before I install it. I did order some of the Remflex gaskets.
 
Glad to help. The dished (concave) side of the valve faces the engine, and it's short-above/long-below the shaft.
 
There's no real "open" or "closed" about it like on a V8 (it only looks like it from this angle) but yep, you've got it right.

Hotbox sealing surface is kinda rough and pitted — makes it extraspecially important to get the good Remflex gaskets for the manifolds-to-head and intake-to-exhaust junctions.
 
I'm going to do a little "smoothing" on the hotbox and use the Remflex gaskets.
I had to helicoil the bolt hole nearest the head. I had to drill out all of the bolts, as it was. I was able to clear the two outside bolt, but had to repair the other one.
Thanks Dan
Norm
 
Dan, quick question...Heat Control Valve...the service manual references a "bumper pad" on the counter weight. I don't remember a bumper pad on my 66 Valiant, of course that was back in the eighties. The manual says "replace the bumper pad if worn or damaged. As you can see, My counter weight does not have one, it is supposed to be on the "mushroom shaped tang" that hits the shaft the coil spring is "hooked" on.
Norm
 
Bill, O blocked mine off on my "dry" EFI intake manifold. Itll get plenty warm contacting the block off plate with those tubes running between the exhaust runners...fuel puddling/atomization is a non issue with port EFI.

IIRC< the bumper stop was a piece of insulation that prevented the heat valve from bouncing, making a ticking noise when you were revving it when the valve was not fully open. Probably just a ring of high temp hose would work.
 
circlepilot said:
Dan, quick question...Heat Control Valve...the service manual references a "bumper pad" on the counter weight
Click to expand...

Little woven-asbestos sleeve on the tang of the counterweight so it wouldn't go "clack" after you rev the engine. It's not necessary for the valve to function correctly, but if you want to have it you can get a piece of woven-silica sleeve (the kind that comes with those heat tube choke repair kits). Hose would be too thick.
 
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This is what I came up with and it seems to work fine. I swedged a piece of soft copper tubing on the tang. I have let the valve "snap back" using my hand without the engine running and the soft copper deadens the sound of it hitting the stop peg.
 
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