Broken exhaust lobe

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Anonymous

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Hi Guys,
I just had my 170 head rebuilt. In the process, the machine shop had to drill out a stripped hole on the top rear lobe. They used a helicoil & it has been fine for a while. Today, the exhaust shop was pulling my manifold off to put my new header on & run my new dual exhaust set up. The bolt seized in the helicoil & snapped the lobe off. I can't afford the cost or time of re-rebuilding that or another head. What are my options?

Thanks,
David K
1963 Comet Convertible
 
8)

Hmmm...Since you dont have time to get it repaired do you have enough of a lip that you put a washer behind a bolt enough to grab it and tighten it down with a nut? Or try JB Weld. It seems to be the magical fix all.
 
is there enough of an edge to mig a bolt there in place of the lip?? I think in this case you may have to get creative.
 
That happens pretty often. You can use a 90% nickel rod to either weld on the broken piece or build it up, then file, drill, and tap to make it like new. If that's not possible, you could use a thick washer and a bolt to clamp the manifold on at that ear.

You could try to MIG it back on, but MIG wire is very hard and the cast iron will end up brittle at the edge of the weld. It will likely snap off69%3in if you do it that way.
 
I have the same problem too! Here's how I attacked my problem. I used a dremel and grinded down the lobe so I could put in a steel tube. I put a washer behind it and then used JB weld to secure. After drying out for a day, I grinded the JB weld and put my header on. Amazingly it worked and the bolt was secure by a nut. I just hope it holds when I get the car running again.


Andrew
 
Ewww, yeah, I hate when that lobe, ear, thing-a-ma-bob piece breaks off. I had it happen a couple of times. :x I definitely agree- J&B weld does the best job that I can think of.
 
Jb weld is only good to 450deg at the most. I think you will be dissapointed if you try it. I would try to get the piece that broke off and take it to a good machine shop that can weld cast iron. You have to put the head in an oven and heat it up to 400deg and pull it out really quick and weld the piece on and then you can surface the head and re tap the hole. Your experience is just a testament to using anti seize on all exaust fasteners it will save you headaches in the long run.

Todd
 
Problem with JB Weld is that it is NOT a true high temp epoxy. Don't get me wrong, it is great stuff...

Try some stuff from this place. More expensive, but IMHO worth it.

www.cotronics.com

They also have machinable epoxy that may help you too.

Slade
 
Go to a real weld shop. You know those hardcore bastards. I work with them everyday. They used a welding rod...I can't think of it right now, but it's used on cast iron. Make sure your metal is preheated and that should do the trick. Of course have them do it..ZZ
 
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