Cracked engine block!!!

   / Cracked engine block!!! #41  
I'm sold on the lock n stitch after viewing thier website. Looks like a good repair if done correctly. Can be done in frame if the crack is accessable. Nice. Thanks for posting that Alan. I will keep that site in mind for my next crack repair.
 
   / Cracked engine block!!! #42  
Wow,
I'm sure you will come out on top in this matter but what a headache to deal with.
What this says to me is go out and check high stress areas and load bearing areas frequently! Might have been an easy fix if caught soon enough.
Keep us informed.
Y&B
 
   / Cracked engine block!!! #43  
Soundguy said:
Funny.. back on post# 14 I mention stitching.. nobody says 'boo' about it. Jump ahead to post # 32.. and it's a 'new' idea...

Soundguy


Well soundguy, don't know what I have done to offend you, but hey, I thought you were referring too the standard type of stitching I had seen where you thread holes, use normal bolts, and weld it back together.

If you were referring to the Lock-n-stitch product that I mentioned, wish you had been a bit more specific.

And I re-read my post and just must be missing where I said it was a "new" idea.
 
   / Cracked engine block!!! #44  
bamatoolmaker said:
I weld cast iron a couple of times every month.We modify and repair iron molds and dies all the time.I would rather replace them with new tooling but that is not a economical solution for my customers.If you can weld steel you can weld cast iron.The biggest problem when welding cast iron is opening up internal gas pockets.When this happens the crack or hole gets bigger.A Lincoln or Miller welder will do the job nothing fancy.Use the highest nickel content welding rods you can find.Set the machine 50-70 amp. neg.DC and practice.I learned how one weekend and had not used a welder in 20+ years.Most of the other posters had good points and I am going to watch the video some day.Speaking from my own experience and I have welded engine blocks.The quality of the iron,the cleanliness and removing the stress points are critical. I say stitch weld it and it should outlast the rest of the engine.I am not trying to be disrepectful in any way to anybody.Oh yeah I also recall the Brits refer to your rear as a bum.


Bama,

I tried to do some crack repair on a transmission housing a couple years ago and was very un-sucessful. (very) One thing that was happening was the casting would erupt a shooting star - just like a spark that you see when grinding. It would fly out 2-3 feet and burst sort of like a firework. No sound of course. It would do this in the areas that were cracked but also in virgin areas of the casting that were ground down to bare metal.

Can you explain what was going on there, I've always wanted to know!

jb
 
   / Cracked engine block!!! #45  
AlanB said:
Well soundguy, don't know what I have done to offend you, but hey, I thought you were referring too the standard type of stitching I had seen where you thread holes, use normal bolts, and weld it back together.

If you were referring to the Lock-n-stitch product that I mentioned, wish you had been a bit more specific.

And I re-read my post and just must be missing where I said it was a "new" idea.

Soundguy shouldn't feel to bad. I mentioned pins and butterfly's shortly after him in post #18, but like him I didn't mention any details. I just figured everyone knew what pinning and butterfly's were.

As far as the Lock-N-Stitch system goes, it works great. I bought all the tools a few years ago and have used it a couple of times. I even repaired a large hole in a diesel race engine block once where a rod tried to escape.
 
   / Cracked engine block!!! #46  
john_bud said:
Bama,

I tried to do some crack repair on a transmission housing a couple years ago and was very un-sucessful. (very) One thing that was happening was the casting would erupt a shooting star - just like a spark that you see when grinding. It would fly out 2-3 feet and burst sort of like a firework. No sound of course. It would do this in the areas that were cracked but also in virgin areas of the casting that were ground down to bare metal.

Can you explain what was going on there, I've always wanted to know!

jb

Sounds like either contamination or a air pocket in the metal. Did you preheat the repair area before welding? Cast should be preheated to about 1000 degrees F before welding. This burns off most contamination that could not be easily cleaned and also prevents other cracks from forming due to the high heat of welding. Welding cast when cold usually leads to poor welds that fail.
 
   / Cracked engine block!!! #47  
john_bud said:
Bama,

I tried to do some crack repair on a transmission housing a couple years ago and was very un-sucessful. (very) One thing that was happening was the casting would erupt a shooting star - just like a spark that you see when grinding. It would fly out 2-3 feet and burst sort of like a firework. No sound of course. It would do this in the areas that were cracked but also in virgin areas of the casting that were ground down to bare metal.

Can you explain what was going on there, I've always wanted to know!

Mabe bad cast iron .Some of the cast iron that comes from china ,etc is not the same cast iron that comes from some of the devloped countries. Some of the cast iron that comes from china , etc, have other matals such as alum. and what ever else that can find to put in it. It's hard to tell without looking at the casting what may have been it .
 
   / Cracked engine block!!! #48  
DieselPower said:
Sounds like either contamination or a air pocket in the metal. Did you preheat the repair area before welding? Cast should be preheated to about 1000 degrees F before welding. This burns off most contamination that could not be easily cleaned and also prevents other cracks from forming due to the high heat of welding. Welding cast when cold usually leads to poor welds that fail.
Yes, the preheat is essential. It relieves the stress and cleans the area. You have to set up an array of torches and preheat the area until it's red. Then go in with high nickel rod and fill. My Dad used to do this for drag racers and it worked perfectly. I remember one Olds block he did that had the entire bell housing broken off. The preheat on that was interesting. Been a while but I think there were six large torches in the array. He also insisted on grinding a V into the crack before starting. I think his biggest concern was the very real possibility of tributary cracks that tended to show up during the preheat. If they are there you shut down and grind them out and start over. No offense to anyone but this is a job for a certified welder that can look at it and tell you with certainty if it is do-able or if you have scrap iron......Won't be cheap either.
 
   / Cracked engine block!!! #49  
john_bud said:
Bama,

I tried to do some crack repair on a transmission housing a couple years ago and was very un-sucessful. (very) One thing that was happening was the casting would erupt a shooting star - just like a spark that you see when grinding. It would fly out 2-3 feet and burst sort of like a firework. No sound of course. It would do this in the areas that were cracked but also in virgin areas of the casting that were ground down to bare metal.

Can you explain what was going on there, I've always wanted to know!

jb

Are you sure it was Iron?What you are describing sounds like magnesium.Ductile iron does contain some magnesium but it should not concentrate in a particular area.If it is an import casting from China,India or Mexico those folks will melt and pour anything they can sell.Do any of you folks remember the radioactive aluminum that we were importing from Russia about 15 years ago?
 
   / Cracked engine block!!! #50  
I would thing you'd have lit magnesium on fire if you tried to weld it with an arc welder.

Could the shooting star have been carbon? That's what makes sparks when grinding ferrous metal, isn't it? Cast iron has a high percentage of carbon.

I'm no expert on welding anything but I have worked with some people who are...engineers from Ohio State which has a very good welding engineering program. The word I got from them when I broke a cast iron housing was that not only it had to be uniformly preheated, but it also had to have a very slow cool-down period after the welding. And then, don't count on it for much.
 
 
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