Yes you can drill the ends of the crack and push soft wire into the holes & 'peen' it in place with a tiny hammer. Or tap and screw small machine screws in it. Don't drive them in too hard.
I've always wanted to try making a dovetail style cut in the cracks of a water jacket and put tiny holes either side, and solder in some white metal. Never have & hope i never have to.
This video, rough, but it worked well.
https://www.youtube.com/watch?v=Er0BZVfzyqk