Can i fix this at home?

Sometimes and in certain situations I guess if the repair is done right, it would more than likely be ok. I just don't trust them in high hp motors. Of course, there can be times when it's for a normal engine [daily driver] with a rare motor it might be the best thing to do. I would not discourage anyone from trying it and would offer any help I could. 30 years ago, I tried to repair some cast pieces for a frame machine for a friend's body shop. I heated the parts with oxy-actalean and Mig welded the parts, they only lasted 2 weeks then broke at the weld points. I guess welding cast has come a long way since then. I am by no means a professional welder.