I want to try and repair this cast iron exhaust manifold from a 1971 477ci Ford Super Duty dual axle grain truck. The previous owner attempted a repair while the manifold was still bolted to the engine. We tried but could not locate replacement manifolds or headers. After the manifold was removed it was sand blasted.
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The 3 types of tig filler wire I considered to use were: Aluminum Bronze, Crown Alloys Royal 55/45-10 copper - nickel, or a new product by Davbro Inc. EZ WELD tig wire.
The manifold was broken in 3 parts and also has a vertical crack in it.
- manifold_3.jpg (115.99 KiB) Viewed 734 times
Has anyone attempted a repair like this? and what would be the method that would be most successful to use.
I was unsuccessful trying to tig this manifold. The excess silicon and carbon in the manifold would pop off and coat the tungsten. What I discovered after drilling a hole at the top and bottom of a crack was the shavings coming off the drill bit looked like black granules of gunpowder no metal spiraling up the bit at all. I think this manifold had a lot of slag in the molten metal when they poured it into the mold during manufacturing.
I ended up brazing it with Crown Alloys 120 nickel/silver brazing rod.
- Bolt lug brazed back on
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There was a large hole in the manifold so I brazed a 1inch by 1 3/4 inch plate on the inside of the manifold before I reassembled it.
- Finished manifold
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After all the work and brazing, the end exhaust port is warped up 1/8 inch, so when we bolt it back on the engine a shim will be needed to get it to seal up. If nothing else I learned a lot from this project.
- warped now have to shim it
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I guess I will have to learn how to make a set of headers
