Manifold removal

[47 dodge 1.5 ton]

Just was wanting to know if there are any tricks when trying to remove the intake/ exhaust manifold as one unit? Seems to be “bolt bound” and unable to get the manifolds split under the carb. I have all nuts/ washers off except heat riser,  no studs came out which is now causing me some pain. Have been at it with a torch, kroil, hammer, and chisel for several hours with no progress. Biggest stud issue is the (2) that go through the exhaust. Just don’t want any broken studs or manifolds if possible. Thank you, Kevin 

[Sniper]

There are 13 bolts/studs you sure you have them all out?

[greg g]

The number of fasteners to remove intake exhaust together is 13.  Some best reached from underneath the car.

[47 dodge 1.5 ton]

I have 13 nuts (9/16 wrench) removed, none of (4) from heat plate.

[Sniper]

Well, there went all my ideas, lol. 

[47 dodge 1.5 ton]

The (2) studs that go through the exhaust manifold have a point on them, what is that used for and why is there no clearance hole around the stud? I removed the nuts on these but think this is my main culprit? Hard to see in picture through mirror, but you can see the point.

[Sam Buchanan]

You may have to get pretty aggressive with breaking the manifolds loose from the studs.

 

Observation; Once you get everything back together...PLEASE get rid of the plastic fuel filter right next to the exhaust manifold!!  ? Proximity to hot engine components is no place for a plastic filter.

Edited December 28, 2020 by Sam Buchanan

[westaus29]

I have disassembled 4 or 5 mopar flatheads and those two studs are often VERY hard to remove but will come out in the end. They are rusted into the manifold and into the block. I once tried drilling one out but very hard steel and could not keep drill straight, damaged the manifold. The studs do not protrude far which makes it worse. The location makes it impossible to get heat where it is needed. Maybe you could get a hacksaw blade in next to block and saw thru the stud but that risks damage to faces. I think the safest would be to soak with penetrating oil for several days then weld a nut onto the stud and use repeated impact in both directions using a six sided socket, maybe with an adjustable torque rattle gun but not too hard. Even when they start to move they are still hard. You can get new manifold fasteners from mopar suppliers.

Edited December 28, 2020 by westaus29
add detail

[Dodgeb4ya]

Those two studs are the worst manifold removal problem IMO on the old flatheads.

Keep on doing what ever you have too.

I had a 1942 DeSoto heat riser job....had to air chisel the exhaust manifold into  pieces  and get another one to finish the job.

Those long rusty studs suck big time.

 

..

[Knaveofdarts]

i was lucky in that the previous worker-onner on my 218 simply neglected to replace those nuts, plus the very bottom center one. So i only had 10 to remove ?

[joecoozie]

Keep prying at them (top and bottom and both ends) and spraying lube on the studs as you work the manifolds back and forth and up and down. They will eventually come off in one piece. Just need patience. I removed the ones on a Chrysler and it took a few days. 

[47 dodge 1.5 ton]

I have several hours in split days so far, nothing broke yet. I have managed to get 3 of 4 heat riser bolts out so far as well. Had to cut the tops off and drive down after soaking and heat. Not sure if it’s worth all the work trying to salvage the intake manifold as it has been welded from the top side only by PO. Don’t think this one has ever been off or they sprayed all holes with a rusting agent! This is the 3rd one I have pulled and by far the worse, had one off in 5-10 minutes. All others had some clearance around the studs that’s why I was questioning if there were some type of inserts originally used? Just getting schooled on patience this week I guess. Thanks for the replies, Kevin

[47 dodge 1.5 ton]

Thought I would update progress, day 5, have the intake off without any damage, exhaust —I have decided to go with a very aggressive approach. This would not have came off by soaking for years. I have cut, chipped, drilled holes, soaked, added heat and still going. Here are some pictures.

[47 dodge 1.5 ton]

This one does not have a heat plate that swivels, only the (2) holes. 

[Dodgeb4ya]

Boy does that look familiar..the last resort?

Ya gotta do what ya gotta do.

[Plymouthy Adams]

Disclaimer:  No tin worms damage in the making of this step by step documentary.  

[Knaveofdarts]

I have a 4-lb engineering hammer I call "The Persuader". I find a viking war cry helps overhead blows land their mark. The wife knows to stay inside until the dust settles.

 

Just don't do what I did, don't throw your cellphone at the TV. They both shattered spectacularly. That was an expensive day.

 

Side note, I actually wasn't aware they made a manifold with that blanking plate. Wonder if thats for certain climates.

[JBNeal]

the good news is that exhaust manifold can be used as a donor for a dual exhaust manifold ?

 

additional information - dual exhaust manifold adapters 

[Sniper]

1 hour ago, Knaveofdarts said:

I have a 4-lb engineering hammer I call "The Persuader".

 

My neighbor, an older gent who is no longer with us, was a Korean war vet.  One day I was out setting fence posts and he offered up an old sledgehammer he used to use to do that "in his youth"  It's a 20lb monster and once I hefted that I told him he must of been a man not to mess with back "in his youth".  I couldn't imagine swinging that thing all day long setting fence posts on the ranch.  He ended up giving it to me, I still have it but I haven't had need to use it in anger, yet.  But those fence posts submitted readily, lol.

[Dodgeb4ya]

If you use a air chisel you can carefully chisel the manifold off the two long studs.

Hopefully the studs will survive...otherwise drilling out those studs will be next.

[47 dodge 1.5 ton]

Day 5– exhaust manifold is off and in pieces, not sure what can be salvaged there. Good news was that I have (1) of the long bolts out as well. Now the 2nd could be a task as it doesn’t budge yet with heat, next to the welder I guess.

Edited December 31, 2020 by 47 dodge 1.5 ton

[50BusiCoupe]

This makes me nervous knowing I’m pulling mine this coming spring to drop in a rebuilt motor. 

[47 dodge 1.5 ton]

I was nervous on this one as well. Back in the spring when I bought this truck the PO said is was real weak the last time they ran it 20 years ago. From what I understood, no one had been in the engine before including adjusting the valves. I could see weld on the intake and they had swapped carbs to a Holley.  After I had the engine running, it was losing power when hot and noticed a vacuum leak when warmed up. I decided I would not touch anything until I had replacement parts in case I would have this trouble. After pulling some replacement parts (manifolds) thought I would be in the clear. I think this goes much easier if the motor had been touched somewhere in life. My advice— just have a plan. 

Edited December 31, 2020 by 47 dodge 1.5 ton