Intake Manifold Cracked

[pot]

I've been chasing down for the better part of the month an issue with 182. The issue was it would never stay running on its own. Without a pocket logger (I've gotten lazy) I just chalked it up to a fueling issue.

Well, today after taking advantage of Labor Day I did a thorough inspection on the ignition components when I came across a pretty long crack on the driver side portion of my smim. I'm going to contact the fabricator to see if they'll repair it let a alone warranty it. I'm happy that I found the problem but not so happy at what the problem is.

I'm curious though, what would cause the manifold to crack? Besides the obvious, too much heat/boost? I don't think the design is questionable /ubbthreads/images/graemlins/dunno.gif

 

[EfiniX]

Knowing where the crack is would help with the guesses, but my first thought was that it was fabricated out of specification and when mounted and bolted in, a slight variance in the shape caused stress that ultimately failed.

 

[iceman69510]

Looks like the split is right down the weld. Is that correct? That indicates a no good weld if so. The parent metal should split or fail first. Seems like a lot of thermal stress is a possibility.

 

[pot]

Yes Dave, that is correct. The split is right down the weld. I understand what effinix is saying however I'd prefer to look a little deeper into the issue. Thermal stress is a strong possibility and was what I was thinking but how?

 

[marvinmadman]

Warped flange from too much heat during welding? Then bolted on really tight to straighten the flange?

 

[EfiniX]

That was my exact thought. Judging by the failure, that weld was dookie.

 

[strokin4dr]

This was a common issue with the Magnus sheet metal intake manifolds. They would split right down the welds just like that.

Is this a Magnus by chance?

 

[jeverts]

We have seen this happen a lot of different things. We has a 1g in here with a intercooler with sheet metal end tanks that blew. Kind of the nature of the beast. Welding does stress the material and depending on the gage metal that is used (.125) is most common the material will still tend to flex and with heat and other factors the weld is typically the weak point. Don't get me wrong if its welded correctly it will work just fine. Thus why I will go to cast or billet because you have much better structure and fewer welds.

The other thing to consider is the type of weld when doing this. Most companies will just bead weld. Were a grove weld is a lot stronger weld because you are "grabbing" onto more surface area of the 2 plates.

I would suggest that you grind a v-groove in the joint there and re-weld it and it will probably hold up just fine. Just make sure the 2 surfaces are clean. Aluminum is not very forgiving when it come to contamination.

 

[holeshotmoe]

^^ My sheet metal IC tank welds split a couple times due to slightly expanding every time under boost.

 

[prove_it]

You need your laptop to flash "Danger to Manifold" while running those two big bottles of nawss...

 

[T3mp0r]

^And live your life a 1/4 mile at a time.

 

[mitsuturbo]

Quoting strokin4dr:
This was a common issue with the Magnus sheet metal intake manifolds. They would split right down the welds just like that.

Is this a Magnus by chance?



Fortunately magnus offers the same lifetime warranty for their SMIMs regardless of original purchaser. It just takes a bit to ship it out and get it sent back after repair.

 

[EfiniX]

Quoting prove_it:
You need your laptop to flash "Danger to Manifold" while running those two big bottles of nawss...

 

[pot]

I appreciate everyone's input -it has been very helpful. This manifold isn't a Magnus and I'd prefer to omit the fabricator until I can talk to them and see if they would be inclined to warranty it. If not, no big deal. I'll just beg jeverts to make me a new one.

 

[GSTwithPSI]

Quoting strokin4dr:
This was a common issue with the Magnus sheet metal intake manifolds. They would split right down the welds just like that.

Is this a Magnus by chance?



Yup. Here was mine when I got it:

 

[jeverts]

Quoting pot:
I appreciate everyone's input -it has been very helpful. This manifold isn't a Magnus and I'd prefer to omit the fabricator until I can talk to them and see if they would be inclined to warranty it. If not, no big deal. I'll just beg jeverts to make me a new one.



I have 2 guys at the shop that want one and another guy that has a VR6 swapped A4 that is getting one because of this same problem. If it didn't take so much time I would probably make them but no one will want to pay for the time that I have into it.