Welding a cylinder head

jambbii

jambbii

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I am putting together a 24 P pump engine. I bought a built 24 head from a member here and it has about 30 cracks in it (thanks globaltuck1). Some of them large. I am out of money to dump in this truck now. I do however have a friend that is a very talented tig welder and is willing to help me out. Is there any special steps I need to go through to make this a permanent fix?

Thanks,

Josh
 
Id be curious as to what filler rod he will use seeing he will be tig welding it. Ive played with trying to tig up some seats in a 12v head, Ive not found a great rod to work with cast yet. Ive stick welded a bunch of cast with the Ni- Rods [nickle] before and had good luck, but not precise enough for welding up valve seats....
 
You can't really weld on Cast Steels. By weld I mean electric arc weld. The differences in temperature and thermal expansion rates through out the heat affect zone cause the metal to become brittle. You will have issues in the weld/HAZ area. That being said, you can give it a shot...but you need to have a high pre-heat and a controlled post heat cycle. Use a high nickel rod or they do make some cast steel specific rods/electrodes out there. Surface prep/cleaning is a must. The best way to do this is to do furnace welding. You heat the entire head up to 2200ish degrees(F) and then using a torch you "weld" the affected area. It’s an art form and I hardly see anyone doing it. We have done it on cast valves using inductive heating and then(using an outside vendor) they use two long holders. One for the torch and the other for the filler material. They weld whatever and then they machine the weld for the correct surface finish.

Thats about the only truely good way to weld on cast steels. I assume your area around the valves have some indications. I would advise seeing if they can replace the seats with a better material opposed to welding(depending upon how big the actual cracks are). Unless you have a cracked head(like a through wall crack) there are other ways to fix the seat area. Not to mention in order to see if you were sucessful or not you will need some sort of surface NDE to ensure you dont have any indications.
 
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A shop I dealt with heats the heads to about 1300, then tigs/brazes them, not really sure. I know they don't stick them.
 
Dont quote me on the numbers, I dont know that those are 100% correct. I have not done and welding procedures nor have I qualified anything for arc welding on cast steel.
 
That's all well and good, but the heads are cast iron, not cast steel.

Big difference.
 
Yes, I guess I should have changed that to cast Iron, as steel implies an alloy of both iron and carbon to some degree. My mistake.
 
Hmm now to find an oven to heat this thing up that hot LOL The cracks are around the seats and some are a couple MM wide ( I think due to getting water in them).

Thanks for the advice!
 
for all the work you are going to go through to weld it is it worth it? It can easily crack again after welding it. I would hate to see you get it back together and not work out for you. I would cut my losses and find another head.
 
I had 4 yrs of schoolin on tig welding, yes you can weld cast. the rod you use is a nickel welding rod for a stick welder knock the flux off of it. you pre heat the material by putting in stove turnin wide open then after welding you put it back in the stove and slowly turn the stove down until it shuts off


but i dont know if this would work on a cylinder head where the valves and stuff are!!!!!! good luck


you would be better off buyin a new cylinder head
 
Have you pressure checked the head to see if the cracks are in the water jackets? If it holds pressure who cares about the cracked seats, and run it. Mine has atleast that many cracks on the seats and injector bores and I have pulled mine like that for 3+ years.
 
cumminslive said:
I had 4 yrs of schoolin on tig welding, yes you can weld cast. the rod you use is a nickel welding rod for a stick welder knock the flux off of it. you pre heat the material by putting in stove turnin wide open then after welding you put it back in the stove and slowly turn the stove down until it shuts off


but i dont know if this would work on a cylinder head where the valves and stuff are!!!!!! good luck


you would be better off buyin a new cylinder head
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Yuck I wouldn't want to use rod that had flux on it for tig. You can buy proper rod for this like ERNiCrMo-2 and others, I've also used some crown alloys rod, can't remember what it was called that has worked well.
 
Did you expect to get a good head when you bought it? I know if I bought a head and it had cracks in it, the last thing I'd be researching is how to fix it. I would be researching who sold it to me and how to return the POS. $.02
 
PASSENGER said:
Yuck I wouldn't want to use rod that had flux on it for tig. You can buy proper rod for this like ERNiCrMo-2 and others, I've also used some crown alloys rod, can't remember what it was called that has worked well.
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Royal 11-10 is a good high nickel tig rod from Crown. It welds cast very nicely. Just pricy at $52/pound. Royal 6 is a good one to use if you're oxy welding it.

My preference for repairing iron heads is oxy spray welding. Works freakin' amazing. This thing is the sh!t ---> Spray Welders by CWT Industries
 
Spray welding is awesome, I almost had a job come in where I would have had my plasma welder setup with spray but it never came through:doh:
 
So, would everybody be surprised to hear a CWI say that cast can't hold a weld?
 
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