Re: Cracked block- how serious is it?

Posted by Owen_Dyneto On 2011/7/23 14:53:54

Lots of choices. If nothing else, for the moment I'd drill a small hole at each end of the crack to spread any residual stress out over a larger perimeter and thus keep the crack from possibly propagating. Try JB Weld to fill the hole and crack, or thread the drilled holes for a threaded plug which can then be cut and filed off flush. JB Weld for the remainder of the crack. Then keep your fingers crossed. Check the oil to insure no internal leak.

Metal stitching as has been mentioned is the classic method for a good permanent fix if you can find someone skilled in the practice. But it requires precision drilling and threading and I'm not sure that such precision can be obtained with the block in the car.

Welding is another excellent solution but done properly for a permanent fix will require not only a skilled practioner but the entire block to be stripped of all internal parts, heated to an elevated temperature for welding with special rods, and then controlled cooling at a prescribed number of degrees per day. Since the heating and cooling of the block could have distorted it, this should be followed with line-honing of the main bearing blocks, possibly decking the block head and pan surfaces, cylinder boring, and perhaps yet more to retrue the block. It's expensive to have done - generally only done for castings which are irreplaceable.

Not much experience with brazing but I have seen similar cracks so repaired that seem to hold up. I have no idea what's involved.

Will some folks will never learn to check their anti-freeze?