Exhaust Manifold Heat Control Valve Missing

[haywire 440]

As shown in the picture the valve and all the parts are gone. Is tapping threads for plugs a good solution?

 

[#41]

I think most people weld them up.

 

[4vnut]

I used allen plugs 24 years ago and still holding up fine.

 

[haywire 440]

Both of those methods are what I’ve heard is good. Since I don’t really weld I was thinking the Allen plugs would work. Thanks for the replies @#41 and @4vnut

 

[haywire 440]

I used allen plugs 24 years ago and still holding up fine.

Did you tap the brass sleeves or remove them and tap the metal?

 

[4vnut]

I drilled them out and tapped the manifold.

 

[sam dupont]

complete rebuild/replace kits are available. Prices are from: Okay!... to Really?

 

[haywire 440]

complete rebuild/replace kits are available. Prices are from: Okay!... to Really?

I know those are hard to come by now a days. I thought a little bit about it but don’t think their needed.

 

[haywire 440]

I’m going the tapping route.

Thanks again!

 

[WileE]

I’m going the tapping route.

Thanks again!

Good idea !

 

[haywire 440]

So, on my first try, I did find brass plugs, 1/4” NC, to fit the brass sleeves. I started tapping the one side of the exhaust manifold through the brass sleeve and on one of the last turns with the tap the brass sleeve spun out. Ooops! I removed the other brass sleeve, as some folks here told me to do, and tapped a 7/16th” NC tap through the holes but then couldn’t find plugs in that size. I could have used shortened bolts but I felt like the tap didn’t cut deep enough.

I asked around some shops about welding it up and was told that cast iron is special and needs to be heated in gradually increased higher temperatures, then welded, then cooled slowly in cycles.

Another fellow said tig welding has special rods to weld it and the cast iron only needs localized heating.

Well he also had 1/4” pipe thread plugs so that is what we used to seal those, now pesky, holes. I coated the manifolds with Slip Plate and will post a photo in a few days.

Thanks for all of the advice.

 

[sam dupont]

I've welded cracked manifolds on a table and mounted on the car. I use a 3/32 308 stainless rod. On the table, I heat the manifold to (it's been a while, so 400 degrees?) make the weld and either put it back in the oven or wrap it with asbestos blanket and bury in the garden (if the old lady is watching. She doesn't like non-food stuff in her oven).

Yours is plugging a hole, so the cooling isn't as critical as a crack. What gets us in trouble is the differing contraction rates of cast and stainless as the weld cools.

 

[Jam72]

I know those are hard to come by now a days. I thought a little bit about it but don’t think their needed.

I am about to replace short headers already on my 72 Charger with stock exh manifolds. Only thing is the heat valve is OK in my replacement one but it’s external spring and attachments are toast. What do replacement parts cost and where can it be sourced? Preferably in Canada. What is the sacrifice if I just weld the valve open or remove it and plug the holes?

I know those are hard to come by now a days. I thought a little bit about it but don’t think their needed.

 

[haywire 440]

Here’s a company in Canada that sells the complete kit. I don’t know if individual parts are available but search Classic Industries, Mega Parts or Google.

National Mo-Parts – Est. 1987

 

[Jam72]

I will probably buy the kit. I could then just reuse the valve and pin as is or install the full kit.How do you remove the pin? Just press or hammer it out?

 

[haywire 440]

Truth be told, I never removed a heat riser valve. I do know there are sleeves that the shaft rotates in. It looks like the kit may not supply those. Hopefully someone else can give you guidance. I think that shaft is just punched out.

 

[pa383mopar]

You need to grind the welds that attach the shaft to the butterfly valve. This will release the shaft so that it can slide out.

The new valve will need to be welded to the new shaft.

More detail in this thread:

Manifolds and flappers!

First off - Can I get the flapper out of the manifold? I have the pieces all off but didn't know how to get the flapper itself out. How and what does this flapper unit do? There is a coil of some sort on one side with a spring and the other side has some type of flint or wire bunch piece...

www.forbbodiesonly.com

 

[440 4 speed]

Here’s a company in Canada that sells the complete kit. I don’t know if individual parts are available but search Classic Industries, Mega Parts or Google.

National Mo-Parts – Est. 1987

View attachment 1547649

They charge in Can$. I have dealt with them since at least 1989 very reputable.

 

[Cranky]

I've seen those things stuck closed before and that's not good. Also seen them where the flap came loose and got stuck down in the pipe half closed. Plus they can rattle as they age. I always took them out on my cars and trucks.

 

[440 4 speed]

I've seen those things stuck closed before and that's not good. Also seen them where the flap came loose and got stuck down in the pipe half closed. Plus they can rattle as they age. I always took them out on my cars and trucks

Any daily drivers with cool temperatures need them. We don’t have one on our 85 Ram B350 360. Even at 70F it needs to warm up after a cold start. If it sticks closed, you can choke the engine.