Crack in block

[Andrew]

Anyone out ther had any luck sealing a cracked block. I was told to try Moroso Ceramic engine sealant. My hopes are not too high, but I'll try it before I tear it down.
There's a 1/4" crack below the motor mount lobe that is weeping antifreeze about a drop every 2 seconds.

 

[65DODGE]

dude try a product called k-seal from an autoparts store this stuff is amazing its in a small blue bottle no draining the coolant required just shake and pour in i sell it at my parts store and everyone i have sold it to has said it has worked beyond there expectations including me using it myself and it will not plug up any thing in the coolant system probably the best product on the market i have seen for coolant leaks and i have seen a lot of different products in my years of being in the business just awesome stuff.

 

[zyzzyx]

cracked block

There is a Tig filler rod made by Eutectic Castolin called Tig Tac I believe. It can be used to repair non-structural cracks (like what happens when your block freezes and pops a small hairline crack. You have to flush out the block, and dry it. V-out the crack with a die grinder so you have a 1/16" gap. Tig weld using this special filler rod. Done! You will have to do some research on who to buy it from, but it's out there. Try a Eutectic Castolin dealer for welding supplies.

 

[arizona satellite]

dude try a product called k-seal from an autoparts store this stuff is amazing its in a small blue bottle no draining the coolant required just shake and pour in i sell it at my parts store and everyone i have sold it to has said it has worked beyond there expectations including me using it myself and it will not plug up any thing in the coolant system probably the best product on the market i have seen for coolant leaks and i have seen a lot of different products in my years of being in the business just awesome stuff.

X2 on the K-Seal, I sell both in my speed shop and have had great response from the K-Seal and only decent from the Moroso product. it is a little spendy( for the size of the bottle that is) but it DOES work. Good Luck

 

[67 B-body]

How high up on the block is the crack?
If it's low enough, you could do a half block fill "hard block". You would never worry about the lower section of the block again! I have heard of folks running half fill on the street with no issues in keeping the engine cool. It is also supposed to stiffen up the lower end a bit helping prevent bearing cap walk from block flex and high loads on the crank.
Might be an option!

 

[Propwash]

If you have a MIG welder you could use wire UTP A8051 Ti to weld it up...Just an idea.

 

[mopar367]

I agree with 67 bbody, use block filler half full in the block. Will seal it right up and stiffen the bottom end.

 

[Andrew]

Thanks, I'll check it out. I know I'm gonna end up tearing back down, but if that buys me a year or 2, that would be nice.

 

[Andrew]

The crack is pretty high on the block, right below the top lobe on the motor mount. will that be a problem?

 

[67 B-body]

Other things come to mind when you say right above the ear for the motor mount.
Is the block structurally sound, or will the crack get worse when you stomp the pedal?
I would be leery of any chemical fixes at this point with all considered. A weld job would be the best kind of repair considering its close proximity to the engine mounts. You might be ok with hard block fill,,, but like you already noted, it's pretty high up and that would most likely a 3/4 fill application. I would then start to get a little worried about keeping things cool enough for street driving.

 

[Andrew]

I already planned on not using that mount and (just bolting thru the other 2 holes for that mount, and putting a torque strap on. (it's on the passenger side). I'm sure I will rebuild it. I just need to buy myself a year tooling around to shows and that while I get some more dough together and swallow the idea of pulling out this freshly rebuilt motor and starting over with a new block. Oh well.

 

[Meep-Meep]

Welding cast iron is tricky and requires preheat and a slow cool down or you will have more cracks than you started with. I would not touch it with an electric welder of any kind. A pretty reliable method that has been done for years is the lock and stitch repair and is most commonly used on industrial diesel equipment. You need to find both ends of the crack and drill it at those points so they doesn't spread then put a plug in the holes. Overlap the first plug with the next one an so on until the crack is gone. An automotive machine shop supply store like Goodson will have the special tapered cast iron plugs, drills and taps to do the repair properly. If you will just use a block sealer to stop the water leak then I'd run a motor plate off the water pump, even on that one side, as an added measure to remove stress off that mount. I'd still drill a small hole at the end of the cracks though.

 

[charger360]

meep is on the right track it is time consuming but works very well. cast is a pain to weld and for you to get it clean enough without pulling it and pretty much tearing it down will be tough. sorry you have this problem. did you check the block before the build?

 

[QTR MILE]

If the block is not #'s matching than I hate to say it however scrap it. IMO it doesn't matter who weld's it, always gonna be a headache. Best of luck.

 

[shag766]

Welding cast iron is tricky and requires preheat and a slow cool down or you will have more cracks than you started with. I would not touch it with an electric welder of any kind. A pretty reliable method that has been done for years is the lock and stitch repair and is most commonly used on industrial diesel equipment. You need to find both ends of the crack and drill it at those points so they doesn't spread then put a plug in the holes. Overlap the first plug with the next one an so on until the crack is gone. An automotive machine shop supply store like Goodson will have the special tapered cast iron plugs, drills and taps to do the repair properly. If you will just use a block sealer to stop the water leak then I'd run a motor plate off the water pump, even on that one side, as an added measure to remove stress off that mount. I'd still drill a small hole at the end of the cracks though.

X2 and i have only met a couple of people that can weld cast.

 

[zyzzyx]

cracked block

Here is a pic of an inboard four cylinder GM engine. Alot of people accidently leave water in their engines over the winter and they have the same problem. I fixed this one last summer with three sticks of the tig wire I mentioned before. This one is a little larger! Good luck!

 

[Andrew]

The crack happened after the motor was built. I tightened the motor mount without the sleeve to keep them apart. I didnt realize the crack went to a water jacket, so I had it welded just to stabalize the crack. I had no intention of using the mount once I cracked it even with the weld because I didn't trust it. After I put the motor in and test drove it I noticed the antifreeze drip. I then strategically relocated some of my tools and said some bad words.

 

[67 coronet]

i realise your problem is serious but when i read..."stratigically relocated my tools..."i almost fell out of my chair laughing.thanx,i needed a good laugh!

 

[91hybrid]

Lock and stitch make kits for repairing cast iron.

http://www.locknstitch.com/

Check out their website.

John