Can we make a exhaust/intake manifold sticky? (2 Viewers)

[UGA2018]

I have some manifold questions that I am hoping MUD can help me with and instead of creating a new thread I thought I might as well add to this one.

I've been working on a desmog and while I was in there decided to pull the manifold off to have them resurfaced and put new gaskets on. The flapper plate between the intake and exhaust manifolds was toast and falling a part so I pulled the two a part and need to replace that plate and gaskets.

Before I take it to get resurfaced I want to put the new plate and gaskets between the intake and exhaust and try my best to line up the two so that they are as flat as possible. Also, I need to take out all of the studs to replace them with new OEM ones that I am ordering.

Here's my questions:

1. Should I use RTV in addition to the gaskets on any of the manifold or is that overkill?
2. Is there specific torque for the bolts that secure the two manifolds together. I think no but want to confirm with you guys.
3. Any tricks to getting the manifolds to line up nice and straight before I bolt them tight together and take into the machine shop?
4. Is there a need to replace those springs and rings in the swivel arms? They look fine and the OEM's are pretty expensive. I would like to avoid that if so but don't want to find myself pulling this back a part down the road for that.

Thanks MUD! Appreciate your help.

 

[UGA2018]

Oh... one more question.

I read that the best way to get those studs out is to put two nuts on them and unscrew the inner nut. Does anyone know the right size nut for this trick? Thanks again!

 

[hank14]

1. Should I use RTV in addition to the gaskets on any of the manifold or is that overkill?
2. Is there specific torque for the bolts that secure the two manifolds together. I think no but want to confirm with you guys.
3. Any tricks to getting the manifolds to line up nice and straight before I bolt them tight together and take into the machine shop?
4. Is there a need to replace those springs and rings in the swivel arms? They look fine and the OEM's are pretty expensive. I would like to avoid that if so but don't want to find myself pulling this back a part down the road for that.

1. I wouldn't use RTV. Maybe some Copper Coat spray if anything. Are you using OEM Toyota gaskets?
2. I never found a torque value. Based on other gaskets and 1/2 the assembly being aluminum, I think I went with around 25 ft.lbs.
3. Not really. You can try to lay the manifold surfaces on a flat surface to help, but otherwise get it as close as you can.
4. I can't see being in there and not replacing them, as I couldn't tell whether they would still seal up or not. Only option is to replace them or take your chances. Not sure how many others have gone without. Might need to talk to one of the main cruiser mechanics and get their opinion.

Hope that helps!

 

[UGA2018]

Thanks @hank14. Yes I do plan to use all OEM Toyota gaskets. I'll go with the 25 ft. Lbs on the torque for the two maniolds together.

I talked to JimC yesterday and he said that he doesn't normally replace those rings and springs but I wanted to see what others would say. I'd rather not spend the money on them if I don't need to but if I'm going to be back in there in a year I'd rather do it now!

Any tips on cleaning the manifolds up? I don't plan on having a shinny perfect engine bay but do want to clean them up some and make sure I clean out whatever I should inside them to have them operate at their best.

 

[OSS]

I would pull the manifold arms out on each side and inspect the sealing rings & spring action beneath them. The rings won't wear out, but they can rust in place and not dynamically seal the joint.

To remove the arms, spray some penetrating rust busting oil in the joint & get the arm rotating back & forth, a little bit at a time. With enough fiddling & working with it, it will eventually work its way out. Pull the ring & inspect the spring, then clean up the groove with some 600 or higher wet dry sandpaper & penetrating oil so the ring will fit in nicely without binding on crap.

There is a bolt that connects the two manifolds together that screws into the aluminum manifold. 25 ft-lbs is too high for that bolt and risks stripping the soft aluminum threads. Just tighten that one wrist tight. Not too much. The other bolts screw into cast iron, so their stonger. 25 ft-lb is the -maximum- torque that should be applied to a bolt that size.

 

[UGA2018]

I would pull the manifold arms out on each side and inspect the sealing rings & spring action beneath them. The rings won't wear out, but they can rust in place and not dynamically seal the joint.

To remove the arms, spray some penetrating rust busting oil in the joint & get the arm rotating back & forth, a little bit at a time. With enough fiddling & working with it, it will eventually work its way out. Pull the ring & inspect the spring, then clean up the groove with some 600 or higher wet dry sandpaper & penetrating oil so the ring will fit in nicely without binding on crap.

There is a bolt that connects the two manifolds together that screws into the aluminum manifold. 25 ft-lbs is too high for that bolt and risks stripping the soft aluminum threads. Just tighten that one wrist tight. Not too much. The other bolts screw into cast iron, so their stonger. 25 ft-lb is the -maximum- torque that should be applied to a bolt that size.

Great stuff @OSS ! Thank you. I was able to get one of the arms off and saw the rings. They look "ok" but I haven't pulled them off or anything. To get a new set of those it is pretty expensive. Can I clean these up enough to reuse them or do you think I would be crazy not to just replace them while I am in there.

 

[Spike Strip]

As stated, if those rings are not broken or corroded (IIRC they're stainless steel) just reuse them and use some ultra High-Temp RTV (700 degree stuff) when assembling.

 

[UGA2018]

FWIW -- for anyone who has the in/ex combo off the engine... I stripped these two holes - even with antisieze and torquing 25% lower than spec. I guess after 25 years of heating the Aluminum gets kinda brittle... So if you're going to the machinist, ask for helicoil insert in those spots, maybe even all the threaded holes in the intake -- problem gone, future problems eliminated.
View attachment 276401

Hey @Spike Strip ! I know this is a dated thread but I am about to take my manifold to a machinist and thought I would ask him to do this if you think it is a good idea still. Just wanted to check since it's been a while since you posted this.

 

[UGA2018]

L

 

[hank14]

No doubt it would be a good idea- at least some added insurance if you're going to all the trouble of machining the surfaces right now.

 

[OSS]

Mine got stripped by the 2nd to the last guy who worked on it. Definitely have the threads repaired - the aluminum is sooooooft.

Toyota never intended for the manifolds to be separated. Their answer to manifold problems was: Replace. Not a very user friendly design.

 

[UGA2018]

Mine got stripped by the 2nd to the last guy who worked on it. Definitely have the threads repaired - the aluminum is sooooooft.

Toyota never intended for the manifolds to be separated. Their answer to manifold problems was: Replace. Not a very user friendly design.

Thanks @OSS so even those threads that hold the exhaust and intake together huh?

 

[Spike Strip]

Yeah, cheap to do and could save a bunch of hassle trying to do it yourself while manifold is horizontal.

 

[Zack1978]

Did you find a machine shop to reface the manifolds? When I needed to have this done on my 60 about eight years ago, there were no local machine shops that would do this job. I ended up taking my truck to the expert Jim C in OH.

 

[UGA2018]

Did you find a machine shop to reface the manifolds? When I needed to have this done on my 60 about eight years ago, there were no local machine shops that would do this job. I ended up taking my truck to the expert Jim C in OH.

It took me a while but yes. I called a bunch in the area and asked on the forum for recommendations. They all said they couldn't do the work. Then I called the local land cruiser shop that fixes up old ones all the time. They were kind enough to tell me their machine shop. As soon as my parts arrive and I get the manifolds together with the new gaskets and insulator plate I'll take it in.

 

[KTP]

1. Yes. Springs then rings on top.

2. No opinion. Edit: @NeverGiveUpYota used some sort of molasses home moonshine to clean up her exhaust manifold. It turned out pretty well. Maybe she can chime in. Painting the EM is a waste, even high temp paint flakes right off in a few weeks. I suggest leaving it be and enjoy the natural patina.

3. Horns must be attached. The machinist must tack them in place and resurface. This is the difficult part in finding a shop that can do it. Also have the bolt holes machined flat as well. It's very important to find a shop that has some experience with these manifolds. Most will turn you away.

4.
View attachment 1490515

5. I'm not sure there's a torque pattern for mating the two manifolds together. I think you can just cross cross and snug the bolts Gudentight. I'd just duplicate the torque specs above to be safe, since the components are essentially the same. Anyone?

Hope this helps. Good luck.

What book did you get the Exhaust torque pattern from?

 

[Spike Strip]

2F FSM

 

[NeverGiveUpYota]

The FSM’s page link is in my signature line. Flip your phone to the side and the link will be visible.

 

[KTP]

Thank you, Thank you

 

[HemiAlex]

Question:

I’ve got an audible exhaust leak on my manifold. I replaced the donut gasket recently and it didn’t help it as much as i would have thought.

Facing the manifold from the drivers side, if I place my hand behind the outlet facing the firewall I can feel the leak.

What’s back there? Can the riser flap pivot point leak? Is there a bolt or gasket that i can’t see? Unless it’s cracked I don’t know what’s leaking.

I’ve not been up there with a mirror to look around. I’ve got a Cruiseroutfitters heat riser block off and a new oem intake manifold gasket but i don’t think either of those is leaking.