Exhaust manifold

Big_Al · #1 07-31-2005, 08:21 AM

Help! As you can see in the pic below the dip stick, I have a hairline crack...don't hear anything or smell anything either.

Questions...does it need to be fixed...welded...JB weld...
how critical...can I drive it at all...slowly...??????????

Thanks guys/gals...I can alway count on you!

Big Al

Big_Al · #2 07-31-2005, 08:22 AM

Here's another...

zdpzimmer68 · #3 07-31-2005, 08:55 AM

Is it just a superficial crack, it would seem if it was cracked all the way through, some exhaust gases would escape, and discolor the area around the crack. Maybe wire brush the area to find the severity of it. I haven't used JB weld for such a high temp application, but I know there are a few products made for such things. POR-15 makes a repair kit for exhaust manifolds.
Let us know what you find out.

Zim

Mr. Fast Bucks · #4 07-31-2005, 09:08 AM

I agree, doesn't look like it's all the way through yet. I wouldn't worry about it. If you wanted to be pro-active you could remove it and find some one that could repair it (they need to know how to weld cast iron - kinda tricky). It's probably better just to leave it alone at this point, you know what they say about sleeping dogs.......

SteveInColorado · #5 07-31-2005, 12:01 PM

If it DOES start leaking, I've had good success welding all different kinds of cast including manifolds by heating it with a torch until it maintains a very dull red glow and welding it with 7018 or 7014 (for AC). You should remove the manifold and bolt it to something to keep it true, weld it and let it cool down while it's still bolted down. I've welded a vise, an engine block, lots of manifolds, and load-bearing cast housings this way, and they've all held up. I don't think I've EVER had cast rod around when I needed it, but anymore I would just do it with 7018.
Like the others said, I wouldn't mess with it 'til I could see it leaking, though.

Steve.

Brownbagg · #6 08-01-2005, 09:49 PM

just go to a junkyard and get one off a 231

GRQster · #7 08-01-2005, 10:11 PM

Brownbag is the most right but otherwise just to keep it simple, grind it off, and JB weld it and let it sit for at least 24 hours before starting it. It (JB Weld) is awesome stuff. I've fixed small engine blocks with it and it lasted for four years+.

Big_Al · #8 08-20-2005, 11:40 AM

Well, here's the finished product. Got some POR-15 manifold gray paint...thick and gooey. Wire brushed the exhaust manifold and it filled in what is apparently a surface crack. I will keep and eye on it and see if it spreads or gets wider.

Big_Al · #9 08-20-2005, 11:46 AM

and...decided to wire brush the intake manifold and paint it too...looks great and will preserve for posterity.

Thanks for everyone's help.
Big Al

Ammocj · #10 08-20-2005, 03:08 PM

I've had some success welding too cast also.
My first attempt didn't go so well but after hearing about heating it first, that made all the difference. I made a traction bar and welded the bracket to the pumkin on my CJ.
It has taken quite a bit of abuse so far. I keep checking it.
I didn't heat it until it was red though, just until I could see it sweat.
And I used a cheap 110v mig with flux wire.

Al