Exhaust Pipe Wide Band Clamp Question - How Would You Fix This?

[Birken Vogt]

Got a little exciting today - load testing a genset with aftermarket DPF, which was plugged, and blew apart this joint ahead of the DPF. On further inspection it was done very sloppy, nothing lines up, can't get the 2 pieces to go close enough together, originally only 1" clamped in either end of the band. The original band clamp was not tight on either pipe either, 3.5", bolts down all the way and still move it by hand. I took out the center hourglass shaped thing and had to put shorter bolts in it, clamped down both ends tight and still not very tight on the pipe ends and blew off again.

Anyway, being as how I need to put an inch or two of pipe in the middle, too short to add a meaningful section and two band clamps on two joints.

I was thinking cut a couple inches of pipe and find a band clamp that is much longer than the usual 2 bolt kind. Do they make a longer 4 bolt version?

 

[398370]

Don’t know about longer band clamps but that looks like an ideal place for a section of flex pipe and a band clamp on each end

 

[JEVANS]

Perhaps the clamps are too big. Ive used Megaclamps lots in the past, they clamp down so tight it sometimes breaks the spots welds, which doesn’t really matter because by then its clamped tight already, but a proper clamp should be very tight by the time you suck the “retainers” into the seat of the hourglass shaped piece in the middle. Like stretching the metal tight.

 

[JEVANS]

Looked closer at the pic, that clamps too big. Usually when you use a clamp like that, to attach same size pipes the part of the clamp in the gap between the two pipes crushes in a looks shrunk kinda.

 

[JEVANS]

Also cant tell by the picture, but where the bolts go thru it, there should be 3 pieces. The hourglass shape in the middle and two half circle pieces to match the hourglass shape.

 

[MarshallPowerGen]

I'll agree that clamp looks like it was bottomed out and still not holding well, and was incorrectly used to make up the distance instead of holding the two sections together. No shortage of improperly fitted exhaust sections to run into over and over.

From how you describe it, could weld a piece on one end to make up the gap and clamp it like it was.
Pictures may be deceiving; but in a pinch I'd be trying either a short piece of flex or solid pipe just long enough to not interfere with the bends and go over what is there and just clamp with old school exhaust u-bolts to hold it. Guess it all depends on how deep you want to dig in.

 

[Nige]

Don’t know about longer band clamps but that looks like an ideal place for a section of flex pipe and a band clamp on each end

That’s what I’d go for as well. I would say right now that the gap between the two tubes is too short for a section of flexible pipe. Each of the fixed pipes really need the end cut back a few inches to give a flexible pipe installed between them a chance to actually flex.

On a different tack is there any possibility to use slotted holes in either one or other of the fixed exhaust tube mountings to improve/perfect the alignment between the two pipes.?

 

[Birken Vogt]

I need to add: both ends are sweep elbows and are already starting to curve away where the clamp is still grabbing. So I can't cut them back otherwise the clamp would really be onto some curved section.

The one on the left goes up into a giant bolted gasket flange on the DPF; the one on the right is shortly welded to an accordion flex section covered in insulation. Either of these parts would be a pain to mess with.

I am also having difficulty locating a replacement clamp on the internet. I went on Fleetpride and Summit racing and 3.5" does not seem to be a common size.

 

[Truck Shop]

You might try using Torca Duraseal or Accuseal clamps with a short piece of stainless flex.

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[Birken Vogt]

The stainless flex you are suggesting, is that the kind that is spiral made often found in truck exhausts under the cab and such? And then a narrow band clamp as you suggested would tighten the spiral down over the fixed pipes?

 

[Nige]

Could you weld a section of flexible exhaust tube to one or other of the fixed pipes and then use a band clamp on the other end.? If you welded the flexi at one end the fixed pipe could be cut back because it wouldn’t need a straight section of pipe to install a band clamp.

Another possible option would be to cut the pipe on the LH side of the photo back right past the 90-degree bend and install a piece of flex pipe a couple of feet long.?

 

[Truck Shop]

The stainless flex you are suggesting, is that the kind that is spiral made often found in truck exhausts under the cab and such? And then a narrow band clamp as you suggested would tighten the spiral down over the fixed pipes?

Correct-stainless because of the heat at that point, galvanized flex just won't take the heat for
very long.

 

[Birken Vogt]

My local truck supply is just a general NAPA store and not very well stocked with this sort of stuff. Is there a good place online or maybe Sacramento that you can suggest? I guess I will try calling Fleetpride but their web site was not very promising especially WRT 3.5" stuff.

Edit: their search does not turn up the right stuff but when I start making up my own part numbers i.e. substituing 350 for the 400 on a 4" clamp, I am finding closer to what I need.

I think there is enough distance between the pieces I may be able to use a swelled piece of 3.5" hard pipe to overlap the existing both ends a small amount plus take up the distance, and use two lap band clamps on it.

 

[Truck Shop]

Or cut the flange from two of these, butt together and weld.

Walker Exhaust 41862 Walker Exhaust Flared Adapters | Summit Racing

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www.summitracing.com

using one of these.

https://www.amazon.com/EVIL-ENERGY-Stainless-Exhaust-Female/dp/B0743BR3S4/ref=sr_1_1_sspa?keywords=3.5%22+v+band+clamp&qid=1687643026&s=automotive&sr=1-1-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&psc=1

or two flared with.

https://www.amazon.com/Ticon-Industries-Stainless-V-Band-119-08900-0000/dp/B01I47EORK/ref=sr_1_5?keywords=3.5%22+v+band+clamp&qid=1687643248&s=automotive&sr=1-5

 

[Welder Dave]

If the 2 ends don't line up perfectly could you get an exhaust shop to bend you you a slight offset out of a longer piece and then cut it to fit and use a clamp on each end?

 

[Delmer]

I ordered a 3.5" in the last year or so, it wasn't hard to find online. If possible, I'd cut one side or the other and weld in a piece so the elbows line up, that seems like the most reasonable solution. I wouldn't want it any more rigid than a band clamp, and it doesn't look like there's room for the corrugated SS wrapped with braided wire style of flex pipe. Galv flex pipe doesn't last long enough.

 

[treemuncher]

Try these guys at SiliconeIntakes.com Maybe this V-band clamp halves will add just what you need.

https://www.siliconeintakes.com/dsm-intercooler-piping/v-band-clamps-p-326.html

 

[JEVANS]

If your looking for clamps try searching Walker Mega clamps.
Made by Tenneco. Didn’t seem too hard to find online.

 

[Labparamour]

You mention: “The one on the left goes up into a giant bolted gasket flange on the DPF”
If welding is a possibility, can you take a small “wedge” cut on the pipe where it mounts to the flange?
That would help alignment and bring ends closer together.
Being flange mounted, might be the easier to remove and adjust.
(Not sure if that made sense…or if it helps)

 

[Birken Vogt]

I'm trying to avoid dragging a welder up in the woods. I have field welded exhaust but it has been several years and have to completely reconfigure the truck to do it. I did find by calling Fleetpride that they had what I wanted local in stock. Their web site was not accurate. When it shows up I think I can modify it to make it work correctly. There are other moving parts to this project besides this, DPF issues and faraway ownership approval.