welding stud hole

[BLOHS7844]

The right most stud for my exhaust manifold was drilled out to like 14mm and still got stripped. (the head is currently taken off of my car btw) I'm thinking I should fill in the hole with a weld (flux core) and then drill with a 13/32 drill bit and tap a helicoli that fits an M10 stud. I tryed twice now but the weld is kinda brittle so when I'm about halfway down it like to break off a chunk. This I know is partially because the weld is kinda rough and not all one piece so the drill bit catches for a second and breaks a piece off. I've already drilled for a solid hour but it's pretty slow. I dip the drill bit in water every couple seconds to keep it cool.

Another option could be to drill and tap it just for the stud, but I know helicoils are stronger and I already have a kit for M10s.

Maybe a 3rd option is drill for the stud, and take a bigger drill bit and drill maybe a third of the way down (right over the top of the smaller hole), tap the smaller/deeper hole for the stud, and fill in the area around the stud with a weld.

I'm dirt poor right now so I have to use a flux core welder and can't take the head into a machine shop. The welds drill pretty good but they can still get brittle and filling it all the way to the bottom is pretty tough.

 

[bryanwheat]

You are never going to get a good weld with a dc welder and no shielding gas. I assume that you are using aluminum wire right? The weld should never break off, it should be part of the head if done right. IF you are going to go that route than you need to take it to someone with a machine that does ac and has shielding gas.

 

[BLOHS7844]

I wasnt using aluminum wire. I thought the fact that it was steel would make it stronger. I do have aluminum wire though. I think it would be too late to switch to aluminum

 

[bryanwheat]

I wasnt using aluminum wire. I thought the fact that it was steel would make it stronger. I do have aluminum wire though. I think it would be too late to switch to aluminum

Do yourself a favor and let someone else do it. You CAN NOT use steel wire on aluminum, that will never work. Also even if you have aluminum wire it will not work right with a dc welder. Take it somewhere or buy another head.

 

[BLOHS7844]

Should I just drill out the weld thats in it then take it to someone? How much would they charge just to fill in a hole
Just to fill it, not sand or drill or anything

Also do u know the distance between the back of the stud hole to the coolant passages?

 

[tkelly27]

You CAN weld Al with a DC wire feed machine. I have done it, there are even some miller machines with sprat arc that can make a weld nearly as nice as an AC TIG machine. You need argon shielding gas and Al wire. I prefer to use .035 wire.

If you've tried to use flux core steel wire on this piece, you're probably not ready to weld up a hole that will be tapped later on in its life. Go ahead and spend $20 and have a shop fill it in for you. They can probably even tap it while they are at it. A good welding shop will run $60-100/hr and probably have a minmum rate. Shouldn't be a lot more than $20, which is a lot cheaper than a new head.

If you want to start weldig Al with your MIG use google and see how people set it uo, but don't practice on your cylinder head!

 

[BLOHS7844]

I'm on a real tight budget and i'm already don't have the money to get the parts to get my car going. I got all of the weld i made out of it. Its still pretty rough on the inside but it's roughly the diameter it was. should I clean up the inside of it?