Jump to content

Broken Manifold


Recommended Posts

My heart sank today. While trying to remove the broken flange bolts the actual flange broke. I tried every trick in the book. Heat, easy out (which did it), candle wax and tapping with 50/50 acetone and ATF. What a bunch of bull***. I work gingerly but never thought in a million years this would have happened. It's too late now but I should have gone with my gut and just drilled out the threads and use a nut and bolt. I will NEVER try unseizing frozen bolts again! Any suggestions what route I could go? Maybe there's a creative machinist or engineer out there.  

IMG_6661.JPG

Link to post
Share on other sites

What kind of car is it? Is it an irreplaceable thing or could another manifold be found that should be in decent condition? I've been through this (believe me!) and I know the frustration. Fortunately, that area might be able to be welded, drilled, and re-tapped to be useful if you can't find a replacement manifold. I wouldn't try welding the little pieces back on, but a competent cast iron welder should be able to apply enough molten metal to that area to create a reasonable facsimile that could be finished to look and act like the original mounting ear.

 

Unfortunately, nobody ever designed these old cars to last this long and the materials used are often well beyond their expiration date, especially something like a cast iron manifold that has been subjected to hundreds of thousands of heat/cool cycles, which is tough. It stinks, but it's not unusual.

 

I'd start looking for a good replacement manifold as a start. Good luck!

Link to post
Share on other sites

If I couldn't find a good one and had to save that one I'd grind off the broken ear and clean up half way around  the exhaust port. Then I would make a semi circular piece with the ear to fit. I would drill, tap, and screw the new piece to the manifold. Probably use  three or four 10-32  screws on each side of the ear. Then I would  also braze the  new piece to the manifold. 

It's a demanding project but if done with care should work.................Bob

Link to post
Share on other sites

Welding cast iron isn't that hard.  Find an old-time welder who specializes in fixing farm equipment.  We have one such person in town and he repaired the same sort of broken ear on my friend's Ford exhaust manifold.  He's also welded a cast-iron drill press base for me and it's been fine for nearly 20 years now. All it takes is using the correct rods. 

Link to post
Share on other sites
10 minutes ago, Summershandy said:

 

My concern is the amount of pressure the bolt will exert when the exhaust flanges are snugged up. Thanks for all your suggestions! 

 

 

That's why I suggested the 10-32 screws in addition to the braze. IMO the way that's broken in pieces it is not a candidate for welding. Of course you could try welding, if that fails than try what I suggested. If that fails you are no worse off.....................Bob

Link to post
Share on other sites

MOST manifolds need to be gas welded unless the iron is in excellent condition in which case Nickel 99 MIGHT stick.

Gray iron filler rod will always stick, won't get hard and will blend in with the parent material.

I welded my share of manifolds and heads.

Don't over think it.

Link to post
Share on other sites
57 minutes ago, cahartley said:

Surely there must be someone up there who can gas weld to fill in the broken area with gray iron rod, grind, drill and tap it.

There HAS to be some resourceful folks up where you are....... ;)

 

Ya I'm gonna check it out and put them to the test. I thank you all with all your thoughts and opinions, you guys rock! I was super bummed today but your posts give me inspiration. I can sleep better tonight. Cheers!

Link to post
Share on other sites

Here is one of the options discussed.

Image result for corvair exhaust manifold fix

 

Or this which is like a saddle around the neck and put in new longer bolts. 

 

Some form or fashion of this repair has been around for Corvairs since the mid 60's.

 

Image result for corvair exhaust manifold fix

 

But I believe that it can be welded with a good welder.

Edited by Larry Schramm (see edit history)
Link to post
Share on other sites
50 minutes ago, Larry Schramm said:

Here is one of the options discussed.

 

Pretty much. But since his is in 3 pieces I would fabricate the piece and make it big enough to accommodate 2 or 3 screws per side and then also braze it in place.  At least that's what I would do but I have a pretty complete shop..............Bob

Link to post
Share on other sites
2 hours ago, Larry Schramm said:

But I believe that it can be welded with a good welder.

Or just a welder who doesn't know better! I have MIG welded stainless steel studs to many a cast iron Corvair manifold with a broken ear just like your picture. Just like the Bumble Bee that cannot fly, it works for me!:D

 

Speaking of the original issue, on Corvair manifolds I never try to remove the rusty remnants of the steel studs, I just cut the remainder stud flush with the ear, center punch as close to the center of the stud as possible, drill with a 5/16" bit and tap 3/8-16. Yes, once in a while the broken stud actually breaks free and turns, but usually around here they are so rusted it is like a solid ear.

  • Like 1
Link to post
Share on other sites
13 hours ago, Summershandy said:

My concern is the amount of pressure the bolt will exert when the exhaust flanges are snugged up. Thanks for all your suggestions! 

And a properly welded repair will be just as strong as original. Don't make this harder than it is.

Link to post
Share on other sites

My suggestion is to repair the original. Muggy Weld offer two grades of arc welding rod for cast iron, one for burnt cast iron (#72) to adhere to the "high carbon" metal and the other (#77) is applied over the #72 weld which can be machined.

https://www.muggyweld.com/knowledge-center/#cast-iron 

They have a number of tutorial videos. I have personally used this and can recommend it with confidence.  Pay attention to the type of arc welding, they want you to use a back stitch motion, which is the way the arc welding rod is held and deposited. You don't have to heat-warm the entire manifold, though I do suggest warming the repair area with oxy-accel (rose bud tip). Then machine as needed.

An article of this topic: http://www.secondchancegarage.com/public4/welding-cast-iron-1.cfm

PM me for more information.

Edited by Friartuck (see edit history)
Link to post
Share on other sites
6 hours ago, Frank DuVal said:

Or just a welder who doesn't know better! I have MIG welded stainless steel studs to many a cast iron Corvair manifold with a broken ear

 

This is so far the best fix idea. Clamp the stud in place  and weld it up solid...................Bob

Link to post
Share on other sites
2 hours ago, Bhigdog said:

 

This is so far the best fix idea. Clamp the stud in place  and weld it up solid...................Bob

Originally they were bolts, but turning it or both into studs all welded up does sound good. 

Link to post
Share on other sites

Brass nuts can not rust in place. OK, technically they can corrode in place, but that bond is easily broken the next time it needs to be removed.

 

Stainless nuts sound like a problem solver, however, stainless nuts on stainless studs (or bolts) gall easily and turn into their own nightmare upon trying to remove them later. Even with anti-seize.:o

  • Like 2
Link to post
Share on other sites
1 minute ago, Frank DuVal said:

Stainless nuts sound like a problem solver, however, stainless nuts on stainless studs (or bolts) gall easily and turn into their own nightmare upon trying to remove them later. Even with anti-seize

 

Exactly correct. You sound like you know what you are doing....................Bob

Link to post
Share on other sites
4 hours ago, Frank DuVal said:

Stainless nuts sound like a problem solver, however, stainless nuts on stainless studs (or bolts) gall easily and turn into their own nightmare upon trying to remove them later. Even with anti-seize.

 

THIS!

 

Never, ever, ever use a stainless nut on a stainless bolt unless you are forced. If you are forced, use a LOT of anti-sieze. Stainless on mild steel is ok.

Link to post
Share on other sites
35 minutes ago, joe_padavano said:

We still don't know what engine this fits or if a replacement is readily available as opposed to all this discussion.

Sorry Joe....it's off a '54 Pontiac Star Chief straight 8 engine. Replacements are hard to find. I'm going to attempt getting it repaired locally first. Thanks. Lot of good ideas posted here on repairs and at best keeps me optimistic. 

Link to post
Share on other sites
  • 2 months later...

Guys, I haven't forgotten you. The machine shop is taking their sweet time. I told them this car was a winter project. I popped in today and they tried welding a new ear, drilling and tapping but the ear cracked off again. Plan B was to weld a bolt in place as a stud. That they did. I asked if they got the manifold ports machined. That was the whole idea of bringing it in the first place. Had bad leaks and was visibly uneven. They didn't go ahead and do it because of the amount of meat they would have to take of a couple ports. I told them to go ahead. Worse case scenario would be 1/8" of material taken off and I see nothing to cause the manifold not to fit. Carb sits on top and exhaust hangs below. The repair ain't pretty but it's also hard to see anyway.  This may take awhile......

Link to post
Share on other sites
  • 2 weeks later...

My manifold is back from the shop. They thought old cast was the easiest to weld but when they filled it, drilled it and tapped it snapped again. So this was plan B. Lesson learned...when you snap a 63 year old exhaust bolt, instead of trying to ez it out and possibly breaking the flange, just drill it out and either re-tap or just use bolts. A very expensive lesson! 

IMG_6800.JPG

IMG_6798.JPG

Link to post
Share on other sites

When I was in the muffler business years ago I could take a broken off stud like that, blow it out with a torch and never touch the threads. Working under the car with the manifold in place. There is a knack to it, but not as hard as you might think because the steel melts before the cast iron. I mention this so you other cowboys will know, if this happens take it to a muffler shop.

 

The bolt is a good idea because it can be knocked out without harming the manifold. Chryslers came this way from the factory. Break off the bolts, put new ones in when you replace the exhaust.

 

Brass nuts won't seize and if they do, can be blow off the stud with a torch easily. Then you run a die over the threads and it's good as new.

Link to post
Share on other sites

Glad to see you got this sorted, and pretty neatly too. My first thought - the casting behind the bolt ears looks round - make a flange out of steel plate (1/4 - 3/8") -  cut a hole that will allow the flange to fit over the cast flange, just, and then rotate it 90 degrees. Downside, if it worked, would be the bolts would be 90 degrees off the original, and wouldnt look that good. Could be tested with a plywood dummy first quite quickly.

jp 26 Rover 9

Link to post
Share on other sites
  • 4 weeks later...

To get the other broken stud out, take a nut and put it over the stub as close to the manifold as possible Then mig weld the nut to the stub.  Let it cool to room temp and it should turn right out.  A shop near me taught me this.  The fellow is 85 and still repairing cast and other farm machinery parts.  Sometimes he takes a 1/4" thick plate of steel 1" by 4" and drills a hole in it, close to one end, to match the broken stud diameter.  Ten mig welds it and used the piece of steel for lever to remove the item.  The nut works well in tight places, where the piece of steel works well in open areas.  If there is a lot of stud left, for a vicegrip to get a good bite, heat the broken stud NOT THE MANIFOLD red hot and let it cool to room temp.  Repeat and then when cooled it should turn right out with the vicegrips.  I have been using this on restoration  projects for over 45 years.

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...