I called Mummerts to ask how they do it. He said they use special rod, and mostly just take a long, long time, many small welds with stress relieving in between. They are cast iron BH's.

 

At my buddy's speed shop they TIG weld cast iron engine blocks and heads regularly. It was a lot more difficult in the old days of scratch welding.

 

Ax can you weld cast if you preheat the cast part almost too the point of destroying it?
If so I bet it messes a lot of parts up

 

I have had cast iron welded by specialists that are set up to weld WITH cast iron rod. You have to essentially weld in an oven at significant temperature and then cool the welded component down very slowly. It is difficult and therefore expensive.
People braze cast iron (basically hot glue!) but not where significant strength is required. Others will use a high nickel rod, better than braze but not as good as the cast iron rod method. I am going to venture out on a limb here and state that believe that the only widely accepted process to repair a cast iron component in significant tension is the cast iron rod method.

 

Guys, seriously. Just Google welding cast iron. People do it all the time. You can do it with a Lincoln AC buz box stick arc welder. Like they said, just have to go slow and stress relieve the weld as you go with your chipping hammer.

 

Crack repairs are common, where basically you just have to stop a leak. To add carbon steel structural supports on the side of a c.i. piece is very unusual. If you are comfortable with it, go for it! Mummert's reputation is very good.

 

I found this thread on jalopy journal. He brazed the new mount points to the cast bell house. Worked fine! Great thread!

http://www.jalopyjournal.com/forum/showthread.php?t=233437

 

Nevermind i think i answered my own question.