Can a Steel Bolt Be Welded into a Cast Iron Manifold?

[Keep it stiff]

I have a three stud cast iron manifold, all three studs snapped off when I tried to remove them. I have drilled out to 8mm and bolts pass through however for one of the three the curvature means that I can't get a nut on. My thoughts are to use nut/bolts as two fixings and have the third stud welded in. I don't weld and I'm told that cast is very tricky.

[Mikeeb]

You can’t tap them and use larger studs?

[mwstewart]

You can do it. It isn't ideal due to the carbon content in the iron, but it should be OK just to hold an exhaust stud in place.

The cast part needs to be heated first.

[Keep it stiff]

Mikeeb said:

You can’t tap them and use larger studs?

That is an option.

[Ambleton]

Use a keensert.

It's like a helicoil on steroids, they're used all the time in castings in OE, motorsport etc.

[tapkaJohnD]

They certainly are!

See: https://www.youtube.com/watch?v=RkACfLjp1Yw

[Keep it stiff]

tapkaJohnD said:

They certainly are!

See: https://www.youtube.com/watch?v=RkACfLjp1Yw

Very useful, mind you my workshop is a bit more basic! Thanks for posting.

[piecost76]

Ambleton said:

Use a keensert.

It's like a helicoil on steroids, they're used all the time in castings in OE, motorsport etc.

Or a Wurth Time Sert

https://eshop.wurth.co.uk/Product-categories/Threa...

[Ambleton]

piecost76 said:

Ambleton said:

Use a keensert.

It's like a helicoil on steroids, they're used all the time in castings in OE, motorsport etc.

Or a Wurth Time Sert

https://eshop.wurth.co.uk/Product-categories/Threa...

There's loads of variants in a similar theme. BMW do (or certainly used to) use Kobserts, but they require fairly specialist tooling. They're pretty cool though.

[ferret50]

tapkaJohnD said:

They certainly are!

See: https://www.youtube.com/watch?v=RkACfLjp1Yw

Very good, thanks for sharing.....love the pooch....