Buick V6 Thread Fix (exhaust)

http://www.earlycj5.com/xf_cj5/index.php?media/c262311b-b19d-4a8f-9109-212b32cc60be.6552/full

http://www.earlycj5.com/xf_cj5/index.php?media/77f2ce55-0236-4d95-88ef-7472022d16a3.6553/full

I removed the original driver’s exhaust manifold for Saginaw over the weekend. I was able to get 5 of 6 bolts out problem free. However, I did snap one. Apparently as I drilled it out, I went a little off course. These pictures are after I ran the tap through the hole. Should I use it as is or attempt a heli coil? What would you do?

Thanks,
blalp

 

A helicoil generally uses high strength loctite and i think it might not work in your situation. If you have already run a tap in there, try and use that size bolt. The heicoil uses a proprietary sized tap AFAIK.

 

If I end up with a manifold leak, I guess another option would be to drill and tap for a larger bolt. This would be assuming that the rear dump manifold can facilitate this.

 

Heli-coils work great to me. But may want to compare the size of the Heli-Coil vs tapping the next size up. Try the smaller one first.

 

Keenserts

KEENSERTS® – Threaded Inserts

 

I just learned something new!

 

Like Helicoils, Keenserts require drilling oversize, but use standard metric taps. I don't think they are availabe for SAE thread sizes though. You could use these, but would have to remember the repaired hole has a metric bolt.
-Donny

 

I’ve coiled many SAE both fine and coarse.

 

get some measurement so you can redrill in the same place. get a mig welder and fill it with cast iron wire. cast usually drills pretty good.