Repair a cracked cast iron intake manifold?

[sykanr0ng]

Can a cast iron intake with a crack across one of the runners be repaired?
The crack is not across a mounting surface and not through any bolt or injector holes but close, it is across the top side of a runner.

 

[spap]

No real stress on an intake and on a fuel injected motor no feel goes through that part of the intake. Prob get it welded pretty cheap don't thing it would be a problem

 

[nickgp]

I did a cast iron exhaust manifold years ago. The trick is to use a high nickel rod and pre heat the part.

 

[Broncobowsher]

Is that an iron marine manifold? Looks a lot like aluminum in the photos.

Personally, for that crack, in an iron manifold. Oxy acetylene torch and brazing rod. I've patched holes in heads between the intake port and the pushrod port that way before. Lets just say the carbide burr was very effective at removing material. End result was it worked perfect. That is a low stress area. No thermal nastiness of trying to patch exhaust manifolds. No need to make it harder then it needs to be.

If you could effectively plug off all the ports and put a good strong vacuum in there (A/C vacuum pump strong vacuum) I would even entertain the idea of just using JB weld and letting the vacuum suck it into the crack. Not first choice, but in a pinch a possible fix that should last forever.

 

[sanndmann3]

If brazing or jb welding, might be a good idea to stop drill the ends of the cracks so they don't continue to spread? Just a thought...

 

[KeithKinPhx]

Why fix? Cost and time you can get a used one from junkyard or craigslist. Heck my original 289 intake has been sitting in a shed wrapped in newspaper since 1995. PM me if you have a way to get from Phoenix.

 

[Broncobowsher]

Because GT40 351 lower intakes are desirable, hard to find, and expensive. You don't just pick them up at any junk yard.

 

[Rustytruck]

A person with a heliarc can weld cast iron with everdur rod. Can arc weld with nirod. With gas torch can braze it with brazing rod and flux. I would bolt the intake to a head with no gasket and preheat very hot. And after welding keep it hot so it cools slowly. Got to be clean, clean, clean before welding up.

http://www.lincolnelectric.com/en-us/support/welding-how-to/Pages/welding-cast-iron-detail.aspx