Exhaust fabrication questions (1 Viewer)

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Ok so I've done some reading off and on relating to this subject. Most of the information on this forum is about exhaust routing, aftermarket brands, exhaust leaks, repairs, etc. It's all good stuff but I have some specific questions about exhaust fabrication in terms of joints. I want to know (preferably from people who work on vehicles regularly or who have done exhaust work themselves) which is the preferred method for joining removable exhaust sections: v-band clamps or gasket flanges?

There's the question. Here's the "why". My 80 needs a new exhaust. It functions as-is but it's loud and it's a patchwork of OEM piping, aftermarket muffler, and some of my own hack-job repairs which were made in an effort to just keep everything working. Sometime in the next year I'd like to try building my own set up. OEM is a nice answer for most things and would certainly be of good quality - but as you all know, OEM exhaust components are way overpriced. Add to that the fact that factory routing isn't the best, the addition of a turbo (possible future mod) requires cutting a factory downpipe, and a few other off road considerations and you realize very quickly that taking out a second mortgage for an OEM exhaust makes no sense. So, if I'm gonna try my hand at building my own I want to do as much welding as possible OFF the truck - which means building sections that can then be joined just like any factory system. I like the idea of v-band clamps due to having no gaskets and seemingly easy installation. On the other hand, I wonder if having gaskets might provide a better seal and therefore less chance of leaks/issues.

Open to thoughts, comments, ideas and experiences.
 
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V bands for the win. Ive used them a lot. You may see some complaints from people having leaks but its usually due to welding them on wrong. If you just slide a flange on and burn the thing on hot it will warp and not seal. When installing them do it assembled with both flanges tightened with the clamp and alternate sides with the weld. I usually just smear a bit of silicone for assembly to make double sure and they are very good after that, and nothing is easier to service later.
 
Joined
Apr 17, 2018
Messages
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V bands for the win. Ive used them a lot. You may see some complaints from people having leaks but its usually due to welding them on wrong. If you just slide a flange on and burn the thing on hot it will warp and not seal. When installing them do it assembled with both flanges tightened with the clamp and alternate sides with the weld. I usually just smear a bit of silicone for assembly to make double sure and they are very good after that, and nothing is easier to service later.
Yeah the serviceability was my main concern since my 80 does and will see plenty of dirt/mud/etc. I didn't know if v-bands would rust up quicker/be harder to replace than a flange type joint.
 
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@Grandlooser you mentioned silicone. Are you talking about smearing some between the v-band flanges before installing the clamp? And do you use any anti-seize/lubrication on the clamp bolts?
 
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You can see some pics of what I did to build my own in this thread.

 
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I prefer gasket flanges. I have quite a few on my exhaust. Nice to remove small sections to do repairs and modifications. I use 2-bolt slotted flanges I buy off eBay. If the exhaust gets a little tweaked offroad or whatever I hope the slotted flanges will allow some minor adjustment and be somewhat forgiving.
 
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I did 3” stainless v bands, they worked well. The only thing I would do different is locate all the v bands suspended from the rubber hangers so the pipe can be removed and installed with just loosening v band clamps. No rusty bolts on hangers to undo if you want to remove a section for installing sliders or whatever later. Use some sort of thread lube, like copper or nickel coat on the stainless fasteners as well.

Getting the exhaust outlet up high and protected is worth the time to get perfect.

I’d recommend a flex joint near the manifold, and another about 3-4’ back to protect pipe from cracking due to engine vibration and movement.
 

mudgudgeon

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I put this together for turbo diesel hzj105.

It was rigid** mounted to the bellhousing and transfer case.

Rigid mounted, but hangers were made to allow thermal expansion along the length of the pipe.

After the transfer case, I put in a long braided flex, then the rest of the exhaust was hung on the OEM rubber blocks.

I had tight clearance to the frame in a few spots, and the v bands made it easy to pass the tail pipe section through between the body and rear cross member where there was 3/4" spare space to get a 3" pipe through.

I used more Vbands at the downpipe end to make it easier to get sections in.

The Vbands I used had a lip and groove on the mounting faces, these give precise alignment.

It makes tacking them, and stitch welding them more important to prevent warping as the fit is much more critical than a flat faced vband.

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