Often times, you get a crack in cast iron that can be repaired, but you don't want to do the lock-n-stitch method for whatever reason. So, this is an alternative method you can easily do. My '28 6HP Fairbanks head had two cracks, so I thought this would be a good time to show what I did. This type of fix is good for broken exhaust manifolds, low pressure water jackets, and any other repairs that are not under high stresses.
If it is a crack and not a break, then drill a hole at the end of the crack. Sometimes, it is hard to find the end of the crack. No problem, take your grinder and V it out first. Then take your torch and warm the area. You should be able to easily see it then. Use a center punch so your drill bit doesn't walk.

Then preheat the area to get it good and warm.

Then fill in the groove with brass.

And let it cool naturally in room temperature air.
DO NOT QUENCH IN WATER! You will undo your work by creating many more cracks! When cast iron cools too quickly, stress cracks form from the rapid shrinkage.

It is also option to perform this task on a Fairbanks-Morse work bench. �;D
