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stuzbot Samba Member
Joined: March 30, 2018 Posts: 377 Location: Pining for the Puddles of Yesterday
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Posted: Sun Mar 31, 2019 8:10 am Post subject: New Exhaust – Making Ends Meet |
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Time to replace my silencer box, which had cracked at the joint with the downpipe. So, on eBay, I found a guy in Poland selling the complete kit [downpipe and silencer] for not much more than other people where selling silencer alone. He had 100% feedback, so I thought I'd take a punt, given that, if the silencer's rotted through, the tailpipe can't be far off doing likewise.
Anyway, first impressions were pretty good. The parcel took only a few days to arrive in UK from Poland and the parts looked to be decent quality; the welding was a bit crude and the silencer was obviously a generic one with brackets welded on to fit the Transporter. But the steel was nice and thick and it seemed well made and matched pretty well with the original.
Anyway, onto this weekend and fitting time and I've run into a problem:
Although all the bolt holes and brackets lined up correctly and everything looked like it was going well, I've been left with a bigger gap than expected and some misalignment where the downpipe and silencer fit together:
As you can see, I've got a couple of cm or around an inch gap there. Now it's not a complete disaster as the brass gasketty washer thing which goes between the two sections is pretty fat:
And there's enough flex in the downpipe that I can, using only one hand, squeeze the two ends close enough together that I could probably 'persuade' it all to join up:
and, with a normal run of the mill exhaust fitting, I'd probably do just that and think no more about it. However, with the JX 1,6TD, the other end of the downpipe bolts to the turbo housing, so I'm a bit worried about forcing the ends to meet as that will be putting some tension into the downpipe and possibly the turbo –although the pipe should flex a helluva lot more than the solid turbo housing.
When I loosen all the mounting bolts; downpipe turbo end and those holding the silencer box in place, I can get the ends even closer together, to the point where it looks like they'd bolt together without difficulty:
But looking from underneath, it's apparent that this is pushing the front-to-back-alignment out instead:
So I'm looking for options and Suggestions now. So far I'm thinking:
1: Reuse the existing downpipe [which of course assumes it's the downpipe that's the culprit and not the silencer box].
2: Bolt everything up using a bit of 'persuasion' and hope that the exhaust heat will temper the metal slightly and allow it to settle into its new position
3: Try to alter the mounting of the silencer box to line up better with the downpipe –using spacers on its mounting bolts or drilling new mounting holes in the bracket on the back of the silencer... or suchlike.
Anybody got any other suggestions or comments?
Putting the usual spanner in the works , when working with these vans [and one reason I'm a bit wary of prematurely jumping to the conclusion my Polski mate has sold me a dud exhaust] is the fact that you're never entirely sure whether or not what you've got on there at the moment is original or has been 'messed with' by a PO.
For example, I noticed this when replacing the rubber mounting plate bolt thingies for the silencer...
The mounting bracket is pressed right up against the oil filler pipe:
So I actually had to loosen the bracket and swing it down so I could get at the back of the bolt holding the rubbery doodad in place:
As you can see, the oil filler pipe has been flattened to allow room for the bolt head:
So, it looks like either the wrong oil filler pipe is fitted, or it's twisted, or the exhaust mounting bracket there is somehow wrong
??? _________________ *****************************
Click to view image
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1992 VW LT35 2,4D [SOLD]
1993 VW LT35 2,4D [SOLD]
1992 VW T3 1,6TD Syncro [SOLD]
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rmcd Samba Member
Joined: October 29, 2010 Posts: 1348 Location: PNW - its a dry rain.
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Posted: Sun Mar 31, 2019 9:02 am Post subject: Re: New Exhaust – Making Ends Meet |
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I don’t understand the whole setup so sorry if this is off base.
Can you weld in a flex pipe in the middle to give it more play in the ends to meet? _________________ VW LT40 build. Like a Vanagon but 30% larger in every direction and 40% slower even in metric.
https://www.thesamba.com/vw/forum/viewtopic.php?t=749359&highlight= |
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stuzbot Samba Member
Joined: March 30, 2018 Posts: 377 Location: Pining for the Puddles of Yesterday
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Posted: Sun Mar 31, 2019 11:14 am Post subject: Re: New Exhaust – Making Ends Meet |
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rmcd wrote: |
I don’t understand the whole setup... |
My bad. I forget the JX engine isn't so common on the other side of the pond. Here's a pic from before I removed the old exhaust:
So the curved downpipe bolts directly onto the turbo housing at one end and the other end is not supported apart from being bolted onto the silencer
rmcd wrote: |
...Can you weld in a flex pipe in the middle to give it more play in the ends to meet? |
...Now. This is odd. I looked for a diagram of the exhaust system and found this in my "folder of useful bits of info":
Unless that's an odd piece of pipe insulation in the diagram [part 10B] it seems to suggest that the original layout does involve a section of flexible pipe at the turbo end –which would allow much easier positioning of the end which connects to the silencer. But, on the other hand would seem to be prone to sagging, given that there wouldn't be any support in the middle of the pipe on the silencer side of the flexi section.
But, if that is the 'proper' setup, then maybe my existing downpipe is a custom job too?
Hmmm.... the plot thickens! _________________ *****************************
Click to view image
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1992 VW LT35 2,4D [SOLD]
1993 VW LT35 2,4D [SOLD]
1992 VW T3 1,6TD Syncro [SOLD]
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DanHoug Samba Member
Joined: December 05, 2016 Posts: 4770 Location: Bemidji, MN
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Posted: Sun Mar 31, 2019 11:44 am Post subject: Re: New Exhaust – Making Ends Meet |
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all the above is why i really like the MV exhaust system... the muffler can be positioned in quite a wide lateral span to accomodate different length cats, etc.
any chance to inexpensively convert? _________________ -dan
60% of what you find on the internet is wrong, including this post.
'87 Westy & '89 Westy both 2.1 4spd
Past projects can be found at--
www.thefixitworkshop.com |
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Alaskaberrys Samba Member
Joined: June 19, 2016 Posts: 1001 Location: SE Alaska
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Posted: Sun Mar 31, 2019 12:02 pm Post subject: Re: New Exhaust – Making Ends Meet |
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stuzbot wrote: |
Unless that's an odd piece of pipe insulation in the diagram [part 10B] it seems to suggest that the original layout does involve a section of flexible pipe at the turbo end –which would allow much easier positioning of the end which connects to the silencer. But, on the other hand would seem to be prone to sagging, given that there wouldn't be any support in the middle of the pipe on the silencer side of the flexi section.
But, if that is the 'proper' setup, then maybe my existing downpipe is a custom job too?
Hmmm.... the plot thickens! |
My imported doka (AAZ w/ JX components) does indeed have a rather hefty piece of flexible pipe in the 10B location. Unfortunately I'm not home now and can't find any pictures of it on my laptop. I can post a few in a couple of days if that will help, but I've zero info on it otherwise... _________________ '91 Westfalia, Bordeaux Red Pearl 2.1L 2wd Auto
'91 T3 Syncro Doka, Escorial Green 1.9L TD AAZ “Gremian” (to provoke, irritate, exasperate, vex...) |
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stuzbot Samba Member
Joined: March 30, 2018 Posts: 377 Location: Pining for the Puddles of Yesterday
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Posted: Sun Mar 31, 2019 12:32 pm Post subject: Re: New Exhaust – Making Ends Meet |
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Alaskaberrys wrote: |
..My imported doka (AAZ w/ JX components) does indeed have a rather hefty piece of flexible pipe in the 10B location.. |
Oddly. I've looked at the offerings by JustKampers and BrickWerks here in UK and both have the downpipe as a single piece. However BrickWerks have a stainless steel version of the exhaust which does have a flexi section. So it looks like both possibilities exist:
JustKampers:
BrickWerks:
BrickWerks SS:
DanHoug wrote: |
...any chance to inexpensively convert?... |
Well, I'm thinking now that inserting a flexi-section is the way to go. Plenty for sale on eBay for around £15 - £20 which isn't too bad:
So, if I can find one the right diameter, I could cut the downpipe and put in a flexi section. A bit annoying because [as is ever the way with these vans] it's going to be yet another "This'll take a couple of hours" job which ends up turning into several days worth of hassle. _________________ *****************************
Click to view image
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1992 VW LT35 2,4D [SOLD]
1993 VW LT35 2,4D [SOLD]
1992 VW T3 1,6TD Syncro [SOLD]
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Last edited by stuzbot on Sun Mar 31, 2019 12:45 pm; edited 1 time in total |
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outcaststudios Samba Member
Joined: February 09, 2015 Posts: 1732 Location: Maine
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Posted: Sun Mar 31, 2019 12:40 pm Post subject: Re: New Exhaust – Making Ends Meet |
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mine has that same piece where it connects back to the turbo, but i thought i thought it was an insulating cover? maybe it is flexible. ill look... _________________ '88Doka JX td
'69 westy
(rip)couple bugs
(rip)three type III"s
(rip) '81 vanagon
a bunch of french stuff,and 9 motorcycles.
https://www.thesamba.com/vw/classifieds/detail.php?id=2573791 |
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stuzbot Samba Member
Joined: March 30, 2018 Posts: 377 Location: Pining for the Puddles of Yesterday
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Posted: Sun Mar 31, 2019 12:52 pm Post subject: Re: New Exhaust – Making Ends Meet |
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outcaststudios wrote: |
mine has that same piece where it connects back to the turbo, but i thought i thought it was an insulating cover? maybe it is flexible. ill look... |
I'm thinking that, if that piece is a flexi, its presence or absence might also contribute to the longevity of manifold nuts and/or exhaust sections.
As has been pointed out to me in another thread, my van is missing the brace that goes between turbo and engine block which is supposed to help prevent the vibration that works the manifold nuts loose.
I wonder what effect on all of this [if any?] having that extra bit of flexibility in the downpipe might have? And did VW start with flexi and switch to one-piece?... or vice versa?... or have both always co-existed? and, if so, why? _________________ *****************************
Click to view image
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1992 VW LT35 2,4D [SOLD]
1993 VW LT35 2,4D [SOLD]
1992 VW T3 1,6TD Syncro [SOLD]
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outcaststudios Samba Member
Joined: February 09, 2015 Posts: 1732 Location: Maine
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stuzbot Samba Member
Joined: March 30, 2018 Posts: 377 Location: Pining for the Puddles of Yesterday
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Posted: Mon Apr 01, 2019 2:42 am Post subject: Re: New Exhaust – Making Ends Meet |
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That looks like some kind of insulation to me. It's completely porous and appears to be wrapped relatively loosely round the pipe, so wouldn't be airtight enough to be part of the exhaust pipe itself.
I wonder if that's what was being indicated on the exploded diagram I posted above. Maybe it wasn't a flexi section after all? _________________ *****************************
Click to view image
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1992 VW LT35 2,4D [SOLD]
1993 VW LT35 2,4D [SOLD]
1992 VW T3 1,6TD Syncro [SOLD]
***************************** |
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Wildthings Samba Member
Joined: March 13, 2005 Posts: 50336
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Posted: Mon Apr 01, 2019 6:04 am Post subject: Re: New Exhaust – Making Ends Meet |
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On my Waterboxers I have added a slip joint in the equivalent pipe so that I can adjust the length and angle a bit. |
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outcaststudios Samba Member
Joined: February 09, 2015 Posts: 1732 Location: Maine
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Posted: Mon Apr 01, 2019 7:03 am Post subject: Re: New Exhaust – Making Ends Meet |
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its definitelt not a flexible section. my experience with exhaust is if you loosen up all the connections and then do a little tightening at a time they all will end up coming together just fine. i wouldnt worry too much about that part. id be focused on getting that stabilizing brace in place to prevent vibration on the whole mess. as you know these diesel jx's really shake, even just at idle. _________________ '88Doka JX td
'69 westy
(rip)couple bugs
(rip)three type III"s
(rip) '81 vanagon
a bunch of french stuff,and 9 motorcycles.
https://www.thesamba.com/vw/classifieds/detail.php?id=2573791 |
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mini t Samba Member
Joined: March 19, 2018 Posts: 60 Location: Michigan
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Posted: Mon Apr 01, 2019 7:04 am Post subject: Re: New Exhaust – Making Ends Meet |
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why not just get some bolts started in the flanges then take a torch and heat the pipe red hot then tighten the bolts that should relieve any tension you only need that small of a gap to close up. |
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drj434343 Samba Member
Joined: January 31, 2016 Posts: 398 Location: Portland, OR
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Posted: Mon Apr 01, 2019 7:30 am Post subject: Re: New Exhaust – Making Ends Meet |
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I'm no JX expert, but in most of the turbo setups I've seen, there is usually some sort of flex section shortly downstream of the turbo housing to relieve any stress the remaining exhaust may impart. I think the cast iron of the turbo exhaust side generally doesn't like cyclic loading, which can encourage fatigue cracking.
If it were me, I would find a way to minimize that gap before finalizing the installation (heating and bending, flex pipe, etc). |
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Wildthings Samba Member
Joined: March 13, 2005 Posts: 50336
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Posted: Mon Apr 01, 2019 9:11 am Post subject: Re: New Exhaust – Making Ends Meet |
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I agree that the flex coupling should lessen the loads on the turbo, though any kind of joint will help. |
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stuzbot Samba Member
Joined: March 30, 2018 Posts: 377 Location: Pining for the Puddles of Yesterday
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Posted: Mon Apr 01, 2019 11:28 am Post subject: Re: New Exhaust – Making Ends Meet |
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I know that [as others have suggested] I could go round nipping up the bolts in turn and it would likely all squeeze together in the end. But I just don't like the idea of having that tension in there. It would keep niggling at the back of my mind.
mini t wrote: |
why not just get some bolts started in the flanges then take a torch and heat the pipe red hot then tighten the bolts that should relieve any tension you only need that small of a gap to close up. |
That's a thought. I'd have to see how easy it would be to get a torch in there and heat the pipe enough without burning anything else. I''d imagine a fairly large diameter pipe like that would take a fair bit of heating.
At the moment I'm minded to go down the flexi-insert route. It' seems the option which will put least stress on everything around it.
For now, I've just stuck my old downpipe back on, until I decide what to do. I gave it a good rubbing down with a flap disc and, although it was pretty rusty in places, no perforations. So hopefully I'll get a week or two more out of it, til I can tweak the new one.
The old downpipe aligns tight enough to hold the brass gasket ring, without me having to hold the ends together
Old downpipe back in place... for now
outcaststudios wrote: |
...id be focused on getting that stabilizing brace in place to prevent vibration on the whole mess. as you know these diesel jx's really shake, even just at idle... |
Ain't that the truth! And another reason I think adding a flexi section between the two bolted down ends of the system might be a good idea in the long run.
Re the brace; unable to find one to buy locally, I've got some steel bar on order, so I can make something up myself. Since I don't have a welder, it won't follow the official pattern. But I'm sure I can come up with something that only requires the metal cutting and bending into shape. _________________ *****************************
Click to view image
*****************************
1992 VW LT35 2,4D [SOLD]
1993 VW LT35 2,4D [SOLD]
1992 VW T3 1,6TD Syncro [SOLD]
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Alaskaberrys Samba Member
Joined: June 19, 2016 Posts: 1001 Location: SE Alaska
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Posted: Wed Apr 03, 2019 8:28 pm Post subject: Re: New Exhaust – Making Ends Meet |
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Sounds like you might have your situation figured outl now, but I thought I'd post pics of my set up that has the flexi joint installed for reference -
Can see a fair amount of bend made up at this angle.
_________________ '91 Westfalia, Bordeaux Red Pearl 2.1L 2wd Auto
'91 T3 Syncro Doka, Escorial Green 1.9L TD AAZ “Gremian” (to provoke, irritate, exasperate, vex...) |
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