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Discussion Starter #1
I'm toying with acquiring a second set of 351C heads and part of the plan is FILLING IN part of the exhaust ports....

Any experience guys?
 

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to properly weld a head, I believe the entire head needs to be brought up to a pretty high temp, but not sure. I know in the past, guys that modified the Cleveland/Boss heads were using high temp epoxy to fill and recontour the ports. Why not just get the port plates???

randy
 

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A steel wire MIG will likely crack on cast iron even with preheating. Use nickel-based stick electrode. Hardware stores sell this for cast iron nowadays. High temp. brazing rod is another possibility - melting temp above 800 degrees F. for exhaust ports. Recommend evenly warming the whole head via torch up to 125 min. (hot to the touch). Use small passes (weld beads) to avoid distortion/warpage. If you ball peen hammer each bead right after arcing out (the whole bead surface) you'll stress relieve each pass immediately (no cracking/less distortion). Use lower current ranges and smaller diameter electrodes. My BS degree was in Welding Engineering. Good luck. Nickel rod makes it easy! I've reattached exhaust manifold ears this way and they were much stronger than new when I finished.
 

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Nickle rich rods because the molten nickle will penetrate and bond with the pourous cast iron grain......I think it would be better to furnance heat the head for better heat uniformity.

I have also heard of people sawing off a portion of the outter exhaust part of the head (after sonic testing for thickness) this way they would cut into the water jacket.....and fabricating aluminum ports for the missing part.....only thing you would have to custom make some gaskets to seal them.....

Using tin fiberboard you could make a template and send it in to SCE so they could custom design you copper gaskets....wit the CNC machine.....then anneal the gasket with a propane torch and
install.....

lots of work but you could make this work!!!
 

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Discussion Starter #5
Thanks guys.....I read a bit about pure nickel rods last night.....

Maybe I'll start trying to practice stick welding on junk cast iron......it'll be funny....I'm not that good at MIG thus far

Fortunately, the heads I'd like to mod won't be my daily drivers!!
 
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