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Cracked LS1 block

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Old 06-18-2011, 03:00 AM   #1
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Default Cracked LS1 block

Hi guys I have just discovered a crack in my TT LS1 block. It is in a bit of an unusual place as it is in behind the starter on the lower side of the block (see pics). The only thing it is doing is leaking water (no water in the oil and engine runs fine!). I am just wondering if anyone else has had 1 crack here, what may be the cause and should I just weld it up? The engine has about 4000 miles on it, has a head stud kit and runs up to 20lbs (a lot I know! though not often)
Any input would be appreciated.
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Cracked LS1 block-cimg3627.jpg   Cracked LS1 block-cimg3629.jpg   Cracked LS1 block-cimg3631.jpg  
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Old 06-18-2011, 08:48 AM   #2
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I would at least weld it if I were na. Being a boosted car, I would always be wondering when it was gonna let go. That much power puts alot of stress on the block. Would def. not "just let it go"
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Old 06-19-2011, 07:51 AM   #3
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Seems like the best thing to do is weld it to stop the leak. But you got to wonder, what cracks you can't see on the inside. Swapping for a new block might sound extreme but on a boosted engine you don't want to take any chances.
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Old 06-19-2011, 08:21 PM   #4
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how far down does that head stud go?
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Old 06-20-2011, 06:53 AM   #5
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Ls studs pull from the bottom of the block so I'm guessing the crack runs accross the head stud thread.
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Old 06-20-2011, 09:19 PM   #6
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If you just TIG weld it from the outside and the welder gets good penetration (like they should) there's a damn good probability that that stud will not be coming out. May be a good cheap fix.

Could remove the head. Weld and then redrill/tap that head stud hole.

Also looks really close to that water plug there. Might have to remove it to weld the crack and clean it up before putting it back in.

Hard to say how long it will last.
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Old 06-21-2011, 04:33 AM   #7
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looks like your losing some coolant fromt he coolant plug right there as well. I wonder if it isnt more damaged then it appears. IMO if you spend the time now to swap out the block, at least you can salvage all the internal parts....if the block cracks during a run you might not be able to save a damn thing inside that engine.
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