em6 285 head cracked between valves

[rklahs]

I have a cracked head on my em6 285 tip turbine 1987 Mack dm686s. Can i use a head off a 1977 237 675. Thanks Randy

[ranchhopper]

I was told by my friend who runs a diesel shop if the crack runs from the injector hole to the intake valve that's acceptable to reuse but if the crack runs from the injector hole to the exhaust valve it could possibly loose the seat while running and not to reuse it. At the same time I assume any heads cracked between both valves would not be reuseable because the seat could also come loose and drop into the cylinder while running.

[Back In Black Pulling]

There is Places out west that can weld cracked heads

Haven't tried yet but i have 3 i want to get fixed

[rklahs]

Thanks for your reply. do you know if em6 head will swap with a head off a 675 237 hp

[Vladislav]

There is Places out west that can weld cracked heads

Haven't tried yet but i have 3 i want to get fixed

I had one of the heads off my ED519 Lanova cracked.

It comes just at the side of the chamber, not to any of the valve seats.

Looks like there's no way of coolant to go into the chamber by now. But I have no idea how long it could last.

Making research in the net I found out that it's impossible to weld ANY cast iron by ANY way.

There was an article where a man analized phisical and chemical matter of that fact.

So stitching seems the only way. I don't know how it's good or bad either.

[fullfuel01]

Check the exhaust stud before the swap. Some have both pattern but 237 have 3pm and 9pm stud mounting and tip turbine are like 2pm and 8pm on the clock.

[m16ty]

Making research in the net I found out that it's impossible to weld ANY cast iron by ANY way.

There was an article where a man analized phisical and chemical matter of that fact.

So stitching seems the only way. I don't know how it's good or bad either.

I just had a 318 Detroit head welded up by a company in Chattanooga,TN. They claim to stand behind their work, and offer 100% money back if it doesn't. We will see.

I know for a fact you can weld cast iron, I've seen certified and x-ray tested cast iron welds. Now weither or not it will work on something as intricate as a head is another matter.

Cast iron welding is not something most welding shops are set up to do but it can be done with the proper equipment.

[Dirtymilkman]

I thought they drilled the cracks and pressed rod into them

[mrsmackpaul]

welding heads was once very common in todays throw away world not so common you would have to find the right place most head reconditioning places should be able to point you in the right direction

Once a head is welded if you really cook the motor again the crack will open up I think it has to do with different expansion rates of materials but if you dont cook the motor they last forever

depending on were the crack is it is very common on cool powered Macks to have cracks but they still work fine

As to your question dunno the answer, looks no one else does either might just have to try it and find out

Paul

[Vladislav]

I thought they drilled the cracks and pressed rod into them

Yes, they do.

The thing I don't like they drill through. Right up to cooling passage.

So I wobble between that option and keep as is.

I can get a solid head but need to go to Europe for.

That's the best way though, just not fast enough.

[41chevy]

I just had a 318 Detroit head welded up by a company in Chattanooga,TN. They claim to stand behind their work, and offer 100% money back if it doesn't. We will see.

I know for a fact you can weld cast iron, I've seen certified and x-ray tested cast iron welds. Now weither or not it will work on something as intricate as a head is another matter.

Cast iron welding is not something most welding shops are set up to do but it can be done with the proper equipment.

The reason why most shops say cast iron cannot be welded is the do not have the equipment. First is the rod needed Softweld 55% ni (about $5 or $6 a stick) which has an expansion rate close to cast iron and machinable or Ferroweld rod (about $2 a stick) but it is extremely hard and prone to cracking. Cast iron blocks and heads need to be preheated to a specific temp before welding and re heated after welding with a controlled cooling. All for easing stress and stopping it from cold cracking during the welding. We learned that for my Navy weld Certification for Grummans Aerospace in the early 70's.

[Vladislav]

welding heads was once very common in todays throw away world not so common you would have to find the right place most head reconditioning places should be able to point you in the right direction

Once a head is welded if you really cook the motor again the crack will open up I think it has to do with different expansion rates of materials but if you dont cook the motor they last forever

depending on were the crack is it is very common on cool powered Macks to have cracks but they still work fine

As to your question dunno the answer, looks no one else does either might just have to try it and find out

Paul

Thank you for the thought Paul.

That's what I read about.

Cast iron being welded forms another christal structure in the area it cools off contacting with sorround metal.

It means different physical properties and could crack down being stressed enough.

[david wild]

YO, He asked about swapping heads not welding, do you not read what he asked ??????

[Vladislav]

YO, He asked about swapping heads not welding, do you not read what he asked ??????

It's a kind of off-topic but question-related.

I personally don't know the answer for his question but hope as more we discuss as more people pay attention to the thread and more chances to help the topic starter either.

[Back In Black Pulling]

YO, He asked about swapping heads not welding, do you not read what he asked ??????

Well for your information I don't know if said heads are interchangeable or if the head he needs is available any where so i Gave him another route to think about.

I know how hard it is to find e9 heads , welding is one option i checked in two in stead of just scraping them.

Thank You very Much !

[smorse54]

I have a cracked head on my em6 285 tip turbine 1987 Mack dm686s. Can i use a head off a 1977 237 675. Thanks Randy

Yes , you can use the 675 head on the 676. Steve

[thomastractorsvc]

I have had so far so good luck welding cast using the nickle rod. I have wood burner made out of a 500 gallon propane pig. Start a fire in it and set the part on top after an hour or so digitemp it to the side of the burner if close start the welding process when done throw couple more sticks of wood in and call it a day on the welding. I use a needle scaler to peen it after welding. Low budget and low tech but effective.

[j hancock]

YO, He asked about swapping heads not welding, do you not read what he asked ??????

Thanks for keeping us straight. We almost never go off topic.

[rklahs]

I spoke with a local rebuilder he said no. He said a late model head would work on the old block but old head would not work on newer style block. Couldnt tell me why.

[rklahs]

Hey guy thanks for all your help. It seems to me that i can use old heads as long as the exhaust manifold fits heads and turbo.

[rklahs]

well guys thanks for your help it looks to me that can use old heads new block and old manifold with new turbo. Glue wire staples and duct tape thats got to fix it.

[j hancock]

Here is some info from Mack Fax Volume 4, No. 5 dated 1984 that may be useful for you. I have never talked to anyone about the swap of 685/686 heads but it looks like it is a function in the mid 80's of the location of the bolts for the manifold. "Assuming" this is still the case for 1977 237 to 1987 285 swap.