Working on tearing down the new Hurricane project bike and I found this:

Image 1 | Flickr - Photo Sharing!

Image 2 | Flickr - Photo Sharing!

Looks like an old break because there was epoxy on it.

Thought of a permanent method to fix it without welding.

After looking at the casting I could tell that there was plenty of depth there to drill and tap and put in a longer stud.

I picked up the drill and tap and a 6mm bolt that I could make into a longer stud.

Image3 | Flickr - Photo Sharing!

Image5 | Flickr - Photo Sharing!

I drilled the hole in the head about .75" deeper and tapped the hole with the 6mm tap to about .50" deep.

Image4 | Flickr - Photo Sharing!

The ideas is to get a new base for the stud into the head and then put the broken piece back on the new stud to support the pipe.

Image6 | Flickr - Photo Sharing!

I used some J&B Thread Lock on the new stud:

Image7 | Flickr - Photo Sharing!

Then treaded it into the new threads in the head.

Image8 | Flickr - Photo Sharing!

Then I put J&B Weld on the broken lug.

Image9 | Flickr - Photo Sharing!

And clamped it using a nut on the new stud.

Image10 | Flickr - Photo Sharing!

Should be good to go and with the stud deeper into the head, no worry about it not clamping the header tight.

 

Looks good. Nice writeup. Thanks!

 

I thought others might be able to use this fix idea. I looked all over the web and recommendations were to weld or replace the head. The approach I used here can be done on the bike, and is just as good since the new stud is into the head further. I would suggest using anti sieze on the threads since the stud is locked into the head. Probably a good idea on all the studs. Clean them with a wire brush and put anti sieze on them before assembly.

I think this may be a common problem. I had a broken stud on one of the other ports. I sprayed penetrating oil on it and let it sit overnight and it came right out. I would suspect that the broken lug was a nut that wouldn't come loose and someone just tried to force it. Steel studs in aluminum, especially in an area where heat is high can lock up solid. There is corrosive action here as well with heat and exhaust gases. The aluminum lugs that these studs are in are not very large and protrude pretty far out from the head. Not a good situation when a stud or nut seizes up.

 

That's an excellent repair and write up as well, thank you for sharing! It's nice to see someone take the time to make a good repair instead of trying to patch it back together.. I see that a lot as an auto tech

Can you tell if the bike had been dropped on that side? I was thinking the exhaust manifold might have hit the ground and weakened or broken that area.

 

I hadn't thought of that. It looks like it was dropped on the opposite side, which still might have cause the damage. Thanks for the positive feedback.