Cylinder head welding

[bazookajoe]

I discovered a way to re-weld those problem areas on the cylinder head horns that hold the exhaust manifold. I have 3 cylinder heads that have the area where the bolt goes through that holds the clamp for the exhaust had broken off through the threads. I ground off the rust and heated the area cherry red with a torch in one hand and with a MIG welder in the other started to build up the affected area, maintaining heat all during the welding process. It spattered a bit when welding to the cast iron at first but when it was steel to steel it flowed well. My MIG was using a shield gas too and ordinary wire. I built it up beyond where it needed to be and after a cool down i ground it down into shape,drilled and tapped it,no problems. I tried it on another head and beat on the welded material with a hammer to try to break it off again with no incident, success. I think there are a lot of heads that have been scrapped needlessly. I wouldn't try to weld a crack around the pistons but this worked well.....your thoughts?

[rickf]

Well, not exactly by the book but it worked. I would not heat it up to cherry red though since you will probably find if you put a straight edge on the head it is most likely warped. You want to get it around 550-650 degrees. You can get high nickel wire for a Mig and weld it with that and preheat and that would be a proper weld. If you can do it with the lower preheat and it holds then go for it. No telling what it will do once in use with heat cycling though. Another option if you have the piece that broke off is to braze it, that is plenty strong for something like that and the brass will expand and contract along with the cast iron.

[bazookajoe]

I just made the immediate area red on the tip of the horn red and kept the high heat away from the large portion of the head, those are very good ideas too Rick.

[lpcoating]

Another trick is the peen the weld after to relieve stress. Also, post heating helps.

Guy