Cracked block (1 Viewer)

[rsbcruiser]

First I aasumed it was a leaking head gasket. Then when it was obvious that it was a cracked block I thought it was oil leaking. Now I hear only antifreeze will eat paint like the pic shows. I treated my coolant sys with a block sealer. Plan on cleaning it up and slathering some JB weld on the crack. So, I was thinking just from the pic someone will be able to tell what it is. Looks like it is just to the right of an oil passage (the raised area of the block)Fiddled with the leaked fluid. Honest, hard to tell, looks like antifreeze. IDK for sure. So besides block sealer and JB weld, any suggestiions? Yanking her for welding is last ditch here because she has a fresh rebuild and all (sad story, not going there). (The original picture has been replaced, trust the guys down below, it was awful)

 

[Mace]

new block..

And, that pic sucks..

 

[IDave]

I have been babying a cracked block for about 3 years now. By far, a new block is the most reliable fix.

If you choose to have it welded (or braized) be sure it's dry and on it's side and done by someone who can stand behind their work, 'cause it isn't an easy thing to do. Block sealer and JBWeld slowed the leak, but didn't fix it for me.

 

[lostmarbles]

Gosh. You've made up my mind. I must indeed go to an optomitrist. Errrr. How do you spell that? Well anyway - I must go to an "eye specialist".

 

[Doug_S]

Instead of discarding the block I suggest that you take a look at this site: www.muggyweld.com. They have a welding rod system that makes it within the realm of the home mechanic to weld up a cracked block and have the repair last. It means that you might have to buy another tool (damn!) namely a stick welder.

Good luck!

 

[rsbcruiser]

Instead of discarding the block I suggest that you take a look at this site: www.muggyweld.com. They have a welding rod system that makes it within the realm of the home mechanic to weld up a cracked block and have the repair last. It means that you might have to buy another tool (damn!) namely a stick welder.

Good luck!

Thanks for the tip Doug. slapped the site into my favs. If the JB and block sealer fail, then at least there is an alternative to yank and fix or s****.

 

[IDave]

Muggyweld failed me.

 

[rsbcruiser]

Muggyweld failed me.

Do you know why Idave? Was the crack to big? Stuff didn't work as advertised? You don't have to preheat the block, right?

 

[grant5127]

I've patched a couple of cracked blocks before with Devcon Titanium Putty..... Available at oilfield supply stores....clean and grind down to new metal about a 1" area around the crack....take a cutoff disc and cut a shallow groove in the crack about as wide as the disc.... drill a 1/8" hole in the block on both ends of the crack... drive in 1/8" dowels with the putty applied .... fill the groove and surrounding clean surface with the putty and let cure as instructions state.....Be sure to drain the coolant cause if there is any seepage it'll interfere with the bonding of the Devcon...

 

[rsbcruiser]

One week update.

I keep looking at a spot below the jb weld covering the crack. I'm sure that sucker is leaking. After a week or so, a few heat cycles and no matter how hard I try to see a leak, ya know that sucker IS holding. I don't know if it was the block sealer or the jbweld that did the trick because I did them at the same time. Don't care.

 

[IDave]

Do you know why Idave? Was the crack to big? Stuff didn't work as advertised? You don't have to preheat the block, right?

And we didn't preheat the block. What happened is new cracks kept forming when it cooled after the weld, just what you would expect from not heating the block and cooling it slowly as you would with regular rod. My welding skills are nominal at best, so I had someone with expertise do it. Maybe someone else would have been successful, who knows? But I didn't think it would be a problem from what I understood.

One possible element might have been that we could never be sure the inside of the water jacket was dry (we blew it out with compressed air and rinsed with acetone, but there's all that crud in those old water jackets).

Anyway, it went from bad to worse.

 

[IDave]

And one of the worst things is that the hairline cracks that formed were mostly invisible, and closed, while the engine was cool. All of the leakage occurred after the engine was warm and running. A puddle would form after each time I drove it (varied in size). Then the leakage would stop. But I didn't want to drive far because I couldn't be sure at what rate I was losing coolant.

 

[vtcruiser60]

Here is my thread on a cracked block....a really annoying problem. \\

https://forum.ih8mud.com/showthread.php?t=34217&highlight=cracked+block

 

[Pin_Head]

Stitching pins is the permanent way to fix a crack like this. People have been doing this for about 100 years and I even learned this in the aeronautic fabrication methods class I took in junior college. It is not hard to do. It takes a special drill and tap and about 16 screws for every inch of crack.

Check it out at:

http://www.locknstitch.com/

 

[IDave]

Can I send you my cracked block in one of those USPS mailers, Charlie, so you can stitch it for me?

 

[splitshot]

I have been babying a cracked block for about 3 years now. By far, a new block is the most reliable fix.

If you choose to have it welded (or braized) be sure it's dry and on it's side and done by someone who can stand behind their work, 'cause it isn't an easy thing to do. Block sealer and JBWeld slowed the leak, but didn't fix it for me.

Me too, I've got a 2f ready to drop in as soon as I get more miles out of my f. (It runs so good I can't bring myself to pull it yet).

It's actually hit the heavy casting on both sides of the crack, what are the odds of it getting worse?

 

[Pin_Head]

Can I send you my cracked block in one of those USPS mailers, Charlie, so you can stitch it for me?

Dave,

I don't know that you will get the package rate on that one because it won't fit in the mailer.

It sounds like you have more cracks now that you started with. One thing they teach is to drill both ends of the crack first to stop them from running on you. One of the down sides to welding cracks is that if you don't use a special high nickle rod (or filler) you won't be able to drill the weld because of carbide precipitation in the bead.

The other thing you need for the stitching pins is the drilling jig to space the holes perfectly so that the screws overlap each other.

Charlie

 

[IDave]

It sounds like you have more cracks now that you started with. One thing they teach is to drill both ends of the crack first to stop them from running on you. ...

I actually did the drilling later, when I tried brazing. But what actually happened is, rather than having the cracks run, new cracks would form parallel to the old crack as the metal cooled. The cooling metal would actually pull down and form the new crack. Then I could do that one and yet another one would form above that.

 

[Pin_Head]

Dave,
That is pretty wierd. Must be some strange metallurgy going on. I have brazed a bit of cast iron and I haven't seen it crack upon cooling. The bronze is pretty soft and ductile, so I would think that it would stretch first before the cast cracked. The old welders trick is to peen $hit out of the bead with the pointy end of a chipping hammer while the bead is cooling. This mechanically expands the metal so that stress doesn't build up.

 

[lostmarbles]

Stitching pins is the permanent way to fix a crack like this. People have been doing this for about 100 years and I even learned this in the aeronautic fabrication methods class I took in junior college. It is not hard to do. It takes a special drill and tap and about 16 screws for every inch of crack.

Check it out at:

http://www.locknstitch.com/

Thanks Pin_head.
I almost wish I had a cracked block to try out that stuff!