Another crack !!

[baggers]

The 2.0 / 2.2 exhaust manifolds are prone to cracking and mine had a 60mm crack in it. Options where to replace with a new one that in time will crack again or take a chance on repairing, I decided on the repair.  Bugger me the crack is back and right through the weld.
Totally guessing here but looking at it what's your thought on these cracks being caused by frequency? these manifolds always fail.

[Steve B]

Think i remember reading that for a weld to work on cast iron,the manifold needs to be at a very high temp for it to work...

[Andy B]

As BIGtime says, the manifold needs to be HOT before you stick weld it. I've welded cast and it's cracked almost immediately along side the new weld.

[Steve B]

And then it will still fail 

Whats that welding they done in the black and white days where they drilled the crack and made it bigger and then put like wedges in it...it was a skill on its own...a real craftsman sort of thing 

[dbug]

Cold stitching,Metal stitching or metalocking - all the same process to repair cracks in cast iron, particularly old engine blocks or heads.

[aaronjb]

Cold stitching,Metal stitching or metalocking - all the same process to repair cracks in cast iron, particularly old engine blocks or heads.

It's a fascinating process (been shown on Car SOS a couple of times): https://www.metalock.co.uk/typical-on-site-repairs/metal-stitching.aspx

[Kevin Wood]

A colleague of mine had it done on an Alvis straight 6 engine block once. Beautiful job. Could clearly see where the stitching has been done, but close your eyes and feel it and you wouldn't know.

[frostbite]

Did you also have studs snap?

[baggers]

No, fortunately they all came undone, it's not the nicest of jobs drilling out the front studs.  All the studs have been replaced.

[frostbite]

Lucky you. I get valve slap in the morning, sounds really rough till it warms