Lincoln SA-200 / Exhaust stack

Well, I went ahead and got the SA-200. The seller got it running and it
started, ran and welded nicely. (He said the choke had stuck on it.)
He kept the battery (after negotiations, don't know if that was original
intention) and the exhaust stack was loose. I appreciated the machinist
friend's offer to let me use his equipment, but prefer having it
available whenever I need it without having to go get his.
The exhaust stack was welded to a 1 1/2" pipe coupling which was screwed
onto a 1 1/2" x 4" pipe nipple. The nipple had been "brazed" to the
exhaust manifold but it had come loose. There is no evidence, that I
have seen, that the exhaust manifold was penetrated at all with the weld
which seemed to just stick to the nipple.
Question: How is the best way to put this back onto the manifold? I
considered: 1) TAP the manifold for 1 1/2" pipe and just screw it in.
2) Design some kind of bracket for the nipple to screw into and then tap
a couple of holes (? 3/8" or 1/2") into the manifold for this to bolt
on. 3) Attempt a weld to the manifold, as was attempted before.
A diesel mechanic told me that I'd probably have to tap the manifold as
not much would weld to it, as far as he knew.
One other alternative - a "press fit" - for the exhaust stack or the
nipple to press into the manifold. Here I suspect I'd have to be
careful about splitting the manifold if too much pressure is applied.
I'm open to other suggestions. There's no rush. It will be a spare
time project. I currently have a Campbell's soup can sitting over the
hole to keep water out of the engine.
I expect the diesel mechanic is correct, but wanted to check for all my
options here.
Reply to
Al Patrick
Loading thread data ...
The braze joint would have failed in any case since the alloy has very little hot strength. You can braze an exhaust system when you are feet away from the engine valve but the exhaust is too hot when you are inches away. You could attempt to weld a new coupling onto the end of the manifuld with Ni-rod but with the trace amounts of bronze alloy you likely will have contamination of your weld. If you can grind away all traces of bronze on the end of the manifold you might try firing the unit up in place to heat up the manifold then clamp on a coupling or nipple and weld it on with Ni-rod. A small little bead around is all you need. Don't get carried away with overwelding. If you can get a large tap and repair the existing thread I would choose that method as plan "A" Consider bracing or supporting your exhaust pipe /muffler so that the strain is off the manifold and joint. Randy
Reply to
Randy Zimmerman
Thanks. It appears the manifold is going to be simple enough to remove and that's what I was thinking of doing - taking it off to repair it.
I will be using a stick welder to weld it, if I weld it at all. I don't have O/A tanks yet.
I was thinking taping the hole out to fit the 1 1/2" pipe nipple might be the best way. There is one question about that however. Would a regular grade pipe nipple (i.e. galvanized, electrical conduit) hold up well enough with all that heat or should I attempt to get a stainless steel or black pipe nipple to fit in there?
Thanks again,
Randy Zimmerman wrote:
Reply to
Al Patrick
Galvanized is going to make a cloud of nasty fumes in a location that hot when the zinc burns off. After that it won't be a problem, but black pipe is pretty easy to come by. You might thank yourself for tracking down stainless and using anti-sieze if you ever need to undo this in the future, but stainless is more of a pain to find, and the anti-sieze will do almost as well with black pipe.
Reply to
I'll plan to take the manifold off, tap it to 1 1/2" pipe size and put in a black pipe nipple - unless I run across a stainless steel nipple of same size, with anti-sieze. I'd have probably forgotten the anti-sieze had you not mentioned it. :-( As far as a brace is concerned it should be simple enough to brace the stack off to the cowling where it comes through. Soooo . . . it looks like I have a little project cut out for myself.
Thanks to all who contributed.
Reply to
Al Patrick
I second the motion for black pipe, you don't want the galvanzed near the block threads. If the exhaust manifold is long and gangly, you need to either support is well with a brace off the engine block or add in a mesh flex line to allow movement. All the bigger gensets use the mesh onthe exhaust.
I much prefer using the standard flange mounts rather than pipe threads in the block. At least the flanges can be removed.
Al Patrick wrote:
Reply to
I'm not sure what you mean by the flange mounts. I didn't see any place for any flange to mount. Anyway, I've picked up a 5" black pipe nipple (shortest he had in that size) and a bottle of anti-sieze.
The stack would not be very long at all if not for the 5" nipple and coupling. It's maybe 14" or so otherwise.
Not sure what I'll do to secure the stack. Perhaps I'll get chance to stop be some construction site and take a good look at how theirs is secured - or look up the mesh flex line on the net.
This one is on a trailer, but is VERY heavy for one person to lift and put a block or two under to level it up. It probably needs a flip back jack mounted on the tongue. Of course, once a new battery is installed on the very rear of the unit it will help to counter balance it a little, but probably not nearly enough.
Again, there's no real rush. . . especially with all the rain expected in NC in the next couple of days. As soon as the weather is expected to be dry for a while I'll pull the manifold and tap it. The rest will be a breeze.
Should I try to get a new manifold gasket prior to pulling the manifold? How available are they for this 50 or so year old Continental engine?
Reply to
Al Patrick
After a search of the net for exhaust and flex line it appears the reference is to flexible hose. I don't think that will be necessary in my case. I was thinking, initially, about just putting a strap from the exhaust to the hood/cowl. After your reference I figured you might be talking about something like a braided grounding strap (i.e. hoods, trunks, and/or lightning rods, etc.) to allow for the movement of the engine within and apart from the cowling, etc. Haven't looked at the motor mounts to see if this could possibly be a problem, but don't think so. Actually, the cowling hole is larger than the exhaust to allow for some movement of the exhaust without bumping the cowling - but is close enough to protect the manifold should the exhaust bump something.
Reply to
Al Patrick
You might find that hand tapping a 2 1/2" pipe thread into the manifold is very difficult unless there are some existing threads to help start the tap. If the manifold is in condition to get good clean metal at the joint, both brazing and nickel welding are widely used for exhaust manifold repairs. Continental engine gaskets and parts are fairly easy to locate. Try NAPA, small engine repair shops, or watch E-Bay. Don Young
Reply to
Don Young
The pipe nipple is only 1 1/2" but I get your point. It will still be hard to hand tap. There are no existing threads - or even weld marks from the previous brazing - that I can see. Someone else suggested nickel rods.
I'll probably just wait till the weather breaks a bit and take it off so I can take a good look at it. Don't know if I'll try to tap it or weld it. I never tried welding cast iron and don't have a good way to heat it unless I put it in the oven at about 400 or 500 degrees. Haven't bought my O/A tanks yet so I can use the torch. There's a welding supply about 15 miles away that'll sell as few or as many rods as a person needs of a given kind.
I may just take it to my friend with the machine shop. He has a large rose bud as well as a 20 x 90" (?) lathe so we could go either way there - welding or taping.
D> You might find that hand tapping a 2 1/2" pipe thread into the manifold is
Reply to
Al Patrick
I've welded smaller cast parts with good results. 99% nickel rod, AC arc, no preheating, and lots of peening of the cooling bead.
Reply to

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.