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Diesel Locomotive Turbocharger Crack Repair

Rick Rowlands

Titanium
Joined
Jan 8, 2005
Location
Youngstown, Ohio
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Recently we acquired an Alco S2 diesel locomotive. It is 69 years old and last ran about 10 years ago, but has been stored inside. It had a cooling water heating system to keep it from freezing up but it failed at some point and as a result there is freeze damage. It appears that the engine itself did not freeze but the rather large turbocharger was full of water in its cooling passages and cracked in two places.

With a locomotive of this age replacement parts are not available, so I would either have to find another Alco being scrapped and harvest its turbo or repair the existing one. The largest cracked area is in the shape of an H and the entire side is bowed out. The second cracked area has a crack about a foot long and extends through a pipe boss.

I'm open to ideas on how to repair the two broken parts. Its a non pressurized cooling system, but is subject to somewhat high temps and lots of vibration.

For the larger broken section, I'm thinking of removing the bulged out sections and screwing a piece of copper plate over the hole as a patch. The copper is malleable enough to be formed to a close fitting shape, and with screws every 3/4" or so around the periphery it should hold on tight.

The other crack is rather long and is problematic because it goes right through a pipe boss. So it needs enough strength to hold the pipe, and with one side bulging out the threads don't mate up perfectly.
 
Firstly i would drain all the water out of the system so no more freeze damage can occur.

There are 4 main methods.

Metal stiching using tapered metal plugs screwed in a overlapping manner.
Bit specialised so would hunt out a person who does this- have a look in the engine reconditioning shops around the place.

Oxy Acetylene gas welding with a cast iron filler rod, this turns out good welds that sometimes cannot be noticed from base metal.

Oxy Acetylene welding with nickel powder a variant of the the method below.


Arc welding with a nickel rod, this leaves a different deposit that has a visible weld, the colour is lighter than the base metal.
Does work.



As your asking the question and haven't seen these methods you better off sourcing the relevant people who have some experience in these types of repairs.
They Could be old tractor repairers, engine reconditions, or skilled hobbyists.
You could try a advert on smokestak.com it is a site of old machinery, engines etc.
I did know jerry appenlapp i think thats how you spell his name was very good a oxy aceteyne welding but not sure is he is still around. Seen a lot of his work posted it is very good.
Thick heavy castings are hard to repair generally as the heat dissipates really quickly and you need to keep the job hot to weld it, makes it tricky.

I have done some myself but no longer in the repair game, hope the info helps.
 
Grind out the cracks ,heat with a torch real hot, Arc weld some econocast 55 in them. post heat and rap on it with a chipping hammer till your arm cant take it anymore.

grind it up and away you go.
 
Be careful with deformation and warping. If its a precision turbo, you will probably reduce the lift of the bearings. If its a journal turbo, it might become harder to start, require more exhaust pressure to run, and be less efficient probably produce less "boost".
Not saying if it warps those things will happen, just be careful.
 
clear out the crack,

Heat up the works and braze it shut.

It can't run that hot if it's got water on it. and nothing accommodates vibration like brass.

If it is practical to remove and strip the turbo housing to better apply the pre heat uniformly , so much the better.

As far as the bulging goes, just beat it down with a 4 # hammer.
 
I too would just clean it and braze it up, no need to do any real grinding on it and you avoid all the HAZ issues that welding brings.
 
I would pull it apart to inspect and see how badly damaged it is. I have Mig welded cast iron manifold repair, modification into turbo manifolds, and turbine housings before. I clean and torch to heat the cast and burn it in. Never had a cracking issue. (These were on much smaller turbine housings )
 
I have mig welded cast just to hold it together for a casting pattern, not under any real stress.
I would not use it for a actual repair as the weld goes dead hard = Brittle.
you cannot file the weld, it is that hard.

As for brazing you have to heat it up reasonably hot to do it, so why not properly weld it?

:typing:
 
First picture was cast iron manifold welded to mild steel pipe and it was stick welded. This was a gas V8 turbo application where temps were likely 1400+ ° and supporting the turbo. Second was a manifold nodded for twin turbos on a diesel. This was MUG welded and also supported the turbos. I have also Mig welded mild steel wastegate /turbine outlet flanges onto cast iron turbine housings without issue.


 
Most shipyards will have the ability to repair it. IIRC, Youngstown is on the PA-OH border, so not exactly on the coast but there must be something at Erie.
 
Its cast iron Stuart.

I don't think that this is your traditional cast iron. It probably is a higher temperature alloy, maybe with some Iconel. If you notice, this does not have the traditional cast iron rust on it and it appears to be much more ductile.

When you go to weld it, you will probably find that the melting temperature, fusing temperature is going to be substantially higher than traditional C.I. This will make it harder in one sense but the weld repair integrity will be better than a straight C.I.

I would recommend finding someone that has some experience with this. It shouldn't be too hard just different. They do weld some of these larger turbo housings up during rebuilds to compensate for exhaust erosion so this is done just not by everyone.

I would also indicate the turbo nozzle bore for concentricity. You might need to relief it in some spots if it has been distorted but I doubt if that has happened. The turbo bearings should be mounted in a separate housing that bolts to this piece so you shouldn't have any bearing problems.
 
Firstly i would drain all the water out of the system so no more freeze damage can occur.

There are 4 main methods.

Metal stiching using tapered metal plugs screwed in a overlapping manner.
Bit specialised so would hunt out a person who does this- have a look in the engine reconditioning shops around the place.

Oxy Acetylene gas welding with a cast iron filler rod, this turns out good welds that sometimes cannot be noticed from base metal.

Oxy Acetylene welding with nickel powder a variant of the the method below.


Arc welding with a nickel rod, this leaves a different deposit that has a visible weld, the colour is lighter than the base metal.
Does work.



As your asking the question and haven't seen these methods you better off sourcing the relevant people who have some experience in these types of repairs.
They Could be old tractor repairers, engine reconditions, or skilled hobbyists.
You could try a advert on smokestak.com it is a site of old machinery, engines etc.
I did know jerry appenlapp i think thats how you spell his name was very good a oxy aceteyne welding but not sure is he is still around. Seen a lot of his work posted it is very good.
Thick heavy castings are hard to repair generally as the heat dissipates really quickly and you need to keep the job hot to weld it, makes it tricky.

I have done some myself but no longer in the repair game, hope the info helps.

Ask and you shall receive. Nice post right to the point full off good information.

Ron
 
I don't think that this is your traditional cast iron. It probably is a higher temperature alloy, maybe with some Iconel. If you notice, this does not have the traditional cast iron rust on it and it appears to be much more ductile.

When you go to weld it, you will probably find that the melting temperature, fusing temperature is going to be substantially higher than traditional C.I. This will make it harder in one sense but the weld repair integrity will be better than a straight C.I.

I would recommend finding someone that has some experience with this. It shouldn't be too hard just different. They do weld some of these larger turbo housings up during rebuilds to compensate for exhaust erosion so this is done just not by everyone.

I would also indicate the turbo nozzle bore for concentricity. You might need to relief it in some spots if it has been distorted but I doubt if that has happened. The turbo bearings should be mounted in a separate housing that bolts to this piece so you shouldn't have any bearing problems.
If this casting houses the exhaust turbine it is likely Ni-Resist. As long as the cracks are just in the water jacket brazing would work fine. I believe Ni-Resist can be welded with a 55% Ni rod.
 
"As for brazing you have to heat it up reasonably hot to do it, so why not properly weld it?"

Because it is impossible to properly pre and post heat for a cast iron weld with this stuff in place. AT least with a braze, you cna just get in there, flow it out and let it be... all you want is water proof caulking, basically. No real strength to worry about here.

Rare as it might be, I must agree that a quick and dirty nickel weld might do the trick here. Preheat with a torch, hit it with a nickel rod and then peen hell out of it. Instead of wearing yourself out with a chipping hammer, needle scaler is the ticket. Weld, drop the stinger and buzz it with the scaler for 20 seconds or so.
 








 
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