Van's EXP119 exhaust flange weld question

[lipper03]

I just received my exhaust kit for my 390EXP119 from my November 2024 FWF order (long story, not this thread), and my first look at the exhaust flanges, as I'm pulling them out of paper, reveal there are gaps from pipe to the flange on all 4 on the engine side of the flange. Outer weld is ok looking, but not a full penetration weld to the entire joint.

This is my first build and it doesn't look right to me from my oil and gas experience, but would like to hear if this is normal. I have asked Van's support as well, that email went out a few min ago, so will post any updates here on that.

Appreciate the second look to help me confirm if there is an issue here or not, thanks!

 

[Mark Dickens]

Good catch, although I'm no expert in this area, I do have an uninstalled set of exhausts (for an IO-360-A1A) from Clint @ Vetterman and they do not have those gaps:

 

[lr172]

Normal. These are not pressure pipes like you are used to (very different welding process). They just put the pipe into the flange and weld only the outside with one bead. There is penetration (you can see the heat markings inside the pipe), but that flange is 1/4" so you don't see that penetration from the top side. It is all at the bottom side of flange. This creates a joint that is more than strong enough for this application. They have been making Tube based headers this way for decades.

 

[lr172]

Good catch, although I'm no expert in this area, I do have an uninstalled set of exhausts (for an IO-360-A1A) from Clint @ Vetterman and they do not have those gaps:

View attachment 97177

In this case, clint is undersizing the holr in the flange and pressing the tube into the flange (better workmanship), so there is no gap between tube and flange. He is not welding it there though. If you look closely, you can see the line between the two parts, showing it was not welded there. Its hard to see because of the grinding (aslo better workmanship - insure a true flat surface).

Clint does really nice work!

 

[stigaro]

Interesting. I received mine a couple months ago after a long delay, but didn't notice this. I will take another look and report back later.

 

[dmattmul]

Mine look ok also. Interested in hearing the outcome. Mine were done by Clint also, I assume he is still doing them? All 6 pretty much the same as below. My 14 had similar looking welding and that was 7-8 years ago.

 

[Mark Dickens]

I had assumed (I know what happens when you assume) that Clint was doing this for Vans...does anyone have any insight into who's doing these exhausts?

 

[lipper03]

I don't know who is making them for Van's, I was told back earlier in the year that some of the delay was a tubing bender in house that was broken, so to me that points to in house made, but I don't know for sure.

Larry did at least make me feel better that I'm not looking for a full penetration along the whole flange, thanks!

But it's looking like the quality of mine might not be as good as others. I'd hate to have a flange leak because of this, and my gap is different than the two examples so far. I'd hate to have the gap large enough that the gasket allows leaks into that space, my guess is that over time it would cause a corrosion issue and eventually leak. So I'm also waiting on Van's response.

 

[lr172]

I don't know who is making them for Van's, I was told back earlier in the year that some of the delay was a tubing bender in house that was broken, so to me that points to in house made, but I don't know for sure.

Larry did at least make me feel better that I'm not looking for a full penetration along the whole flange, thanks!

But it's looking like the quality of mine might not be as good as others. I'd hate to have a flange leak because of this, and my gap is different than the two examples so far. I'd hate to have the gap large enough that the gasket allows leaks into that space, my guess is that over time it would cause a corrosion issue and eventually leak. So I'm also waiting on Van's response.

no leak concerns. the weld bead on the bottom side of the flange prevents that. The bead should cover the full 360 degrees of the seam. If it doesn't, that is a defect. That sealing at the flange will be just fine, as the gasket sits on the flange not the tiny tube area. I have pulled tube manifolds off toyotas that look the same as yours. most do it this way (gaps) because it is easier to set up the assembly in the jig. Clints work is better, but in this application, with the limited amount of use, it is no issue. Not worth throwing out a $1000 part and am sure vans will not consider that defective.

 

[lipper03]

Thanks for the clarification Larry! Sounds like I’m good to go.