Can this crack be repaired?

700rpm

700rpm

Well-known member
What should be done about this? I found a 3/4" crack running from the top center of the water inlet on the side of the block, and about 3/8" into the water jacket. It isn't much more than a hairline. Can this be pinned on the outside and thereby stop the crack? Or is there a better way to stop or seal it? Or should I just ignore it? I've never seen a crack in this area before. What might have caused it? I don't see how it could be a freeze crack.
 
Someone in the distant past welded up a crack in my block in the exact same place. Very nice weld, guy knew what he was doing. Works fine.
 
I've patched simple outer water jacket cracks with JB and NEVER had a problem. I always drilled a small hole at the end of the crack to keep it from running any farther. I would grind a groove in the crack for the JB to fill and spread it slightly so there will be enough material to do a finish sanding job. If the water jacket is real clean it can be brazed with no flux but its got to be clean. If not little spots will apear at the gap that you are trying to fill that look like fish eyes . you won't be able to fill them with brass. After an attempt fails at brazing, JB or nothing else will hold up over the brass. I have got very good service from JB Weld and thats what I would use if it was mine.
 
Purdy Swoft said:
I've patched simple outer water jacket cracks with JB and NEVER had a problem. I always drilled a small hole at the end of the crack to keep it from running any farther. I would grind a groove in the crack for the JB to fill and spread it slightly so there will be enough material to do a finish sanding job. If the water jacket is real clean it can be brazed with no flux but its got to be clean. If not little spots will apear at the gap that you are trying to fill that look like fish eyes . you won't be able to fill them with brass. After an attempt fails at brazing, JB or nothing else will hold up over the brass. I have got very good service from JB Weld and thats what I would use if it was mine.
Click to expand...

As Purdy says....but...If you use JB weld...use the slow set as it seems to grip much better than the quick setting.
Good Day!
 
700rpm said:
What should be done about this? I found a 3/4" crack running from the top center of the water inlet on the side of the block, and about 3/8" into the water jacket. It isn't much more than a hairline. Can this be pinned on the outside and thereby stop the crack? Or is there a better way to stop or seal it? Or should I just ignore it? I've never seen a crack in this area before. What might have caused it? I don't see how it could be a freeze crack.
Click to expand...

It is a stress crack; It can be successfully repaired by pinning.
I would never attempt to weld a block unless you've had years of experience.
This way it's done for a seamless repair.
 
Does it leak water? If not, I'd leave it alone. If it does leak, then if the block is out I would have it pinned with lock-n-stitch pins.

http://www.locknstitch.com/cracked_engine_block_repair.htm

If its in the engine, JB on non stress bearing parts such as water jackets and used as Purdy describes works well. Hint on slow set JB: use blue ,green or yellow 3m masking tape over the product to hold it in place until it sets. Slow set JB runs and sags if it has the opportunity.
 
I patched a 2-3 inch freeze crack in the block of a 305 V8 in a '76 Camaro, right above the starter, in about 1985. I sandblasted the heck out of the area, mixed a whole tube of each part and put it on. I drove the car for a year, my sister drove it to college for a year or two then sold it. That guy totaled it and I never heard of the JB leaking.
 
700rpm said:
What should be done about this? I found a 3/4" crack running from the top center of the water inlet on the side of the block, and about 3/8" into the water jacket. It isn't much more than a hairline. Can this be pinned on the outside and thereby stop the crack? Or is there a better way to stop or seal it? Or should I just ignore it? I've never seen a crack in this area before. What might have caused it? I don't see how it could be a freeze crack.
Click to expand...

Something that looks like this?
Once this is painted it isn't obvious like JB weld and it'll never come back.
This is what I was referring in regard to metal stitching/crack repairs.
http://www.jandm-machine.com/metalStitching.html
 

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J and M Machine said:
We charge from 45-50 dollars and inch so I would say about 100 dollars.
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Thank you. That makes the decision easy, and would be money well spent. I have a long history with my rebuilder and I know he'll be fair with me. I could have —and would have— asked him first, but he was out Friday and I wanted to get opinions here as well. I'll talk to him again on Monday (tomorrow) and we'll discuss the stitching. There are other problems with this block and by tomorrow he says he'll have determined whether it is worth trying to save or not. The answers here will help me go in more informed.
 
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