Date: Tue, 23 Sep 2008 22:51:53 -0400
Reply-To: pdooley <psdooley@VERIZON.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: pdooley <psdooley@VERIZON.NET>
Subject: Re: Help with exhaust bracket design?
In-Reply-To: <c4e7c5f90809231836x65c763cbv5b929c6d6bd1b2c2@mail.gmail.com>
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Neil,
Take a look at the exhaust system on any rabbit/jetta/scirocco/golf/etc..
The entire system is suspended with rubber hangers.
This allows the system to move and absorb vibrations from the motor.
You may find you have a lot less noise, vibrations and harmonics after
building a similar system in your van.
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
neil N
Sent: Tuesday, September 23, 2008 9:36 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Help with exhaust bracket design?
Thanks Jim.
Darn those "bad vibrations"! Shakin' up those metal molecules (I
assume) Your 1" plate comment illustrates that more clearly now.
The exhaust is mounted entirely to the engine. I figured one metal
flex bellows http://tubaneil.googlepages.com/ExhaustBushin.jpg would
suffice. Obviously I missed the point.
I did not know about the isolators needed for the exhaust system.
Unless I misunderstood and you mean the isolators (DV setup) between
the engine carrier bars and frame. I used two Fox rubber mounts
between the engine and the carrier I made.
I didn't know the Vanagon exhaust had isolators. I'll study my Bentley.
Thanks for the pointer to that and the other tips.
Obviously I can't make it strong enough and need to make amends with
the exhaust Gods soon!
:^)
Thanks,
Neil.
On Tue, Sep 23, 2008 at 6:10 PM, Jim Arnott <jrasite@eoni.com> wrote:
> Neil,
>
> When I peeked under your van at Catherine Creek, I saw the potential for
> exactly what you're experiencing. The problem is the engine vibration.
The
> solution is rubber vibration isolators. You need to develop a support
system
> that has a bit of 'give' in it. You could do what you've done in 1" plate
> and all you'll have done is lengthened the time until it fails. Find
someone
> local with a stock diesel vanagon. (Shawn Wright or Tobin Copley come to
> mind.)Take a look at the muffler mounting. You'll note that VW did mount
the
> muffler to the motor (actually to the motor mounting system) and used
> elastomeric mounts. One on the right and two perpendicular to each other
on
> the left. You'll need to come up with a similar system. I'll send you jpg
> of the relevant ETKA page p-mail. You might also chase down Bjorn Ratjen.
He
> has a TDI mounted at 15 degrees and IIRC lives in Vancouver.
>
> Jim
>
> On Sep 23, 2008, at 5:29 PM, neil N wrote:
>
>> Hi all.
>>
>> After repairing my exhaust:
>>
>>
>>
http://tubaneil.googlepages.com/JustForLaffs.jpg/JustForLaffs-full;init:.jpg
>>
>> (yes you can laugh now)
>>
>> I found yet more nagging details. Like broken exhaust brackets:
>>
>> http://tubaneil.googlepages.com/brokenexhaustbrackets
>>
>> I *think* the passenger side breaks are due to me bumping into a hill
>> side whilst escaping from a logging road on my last trip. The driver
>> side likely started to fail due to the increased motion. Plus upon
>> disassembly, I realized I had mistakenly built a little tension into
>> the design. i.e. inlet of cat needs to be pushed a little to line up
>> with the flange on primaries.
>>
>> So I'm hoping engine vibrations aren't the culprit.
>>
>> But if they are ......
>>
>> Does anyone have some pointers on a better design for these parts?
>>
>> I like where they're mounted, and the material should be suitable
>> (1/8" mild steel) but the design may be the fault here.
>>
>> FWIW, the welds held up fine. There is an flex bellows in the exhaust
>> system.
>>
>> TIA for any pointers or pics of successful designs!
>>
>
--
Neil Nicholson '81 JettaWesty "Jaco
http://groups.google.com/group/vanagons-with-vw-inline-4-cylinder-gas-engine
s
http://web.mac.com/tubaneil
http://tubaneil.googlepages.com/