Date: Thu, 20 Dec 2012 18:39:59 -0800
Reply-To: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Subject: Re: Diesel Vanagon Exhaust Design
In-Reply-To: <CAB2RwfjFmmPvD3hZYWJwnvWd66rhhOPVRg-R=LkO_QOqXD26HA@mail.gmail.com>
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YES, of course.
That and ...*all* rear engine VW's since god invented them ....right at
the end of WWII ( as we know them )
have had their entire exhaust system mounted to the engine.
for sure it's to eliminate having to allow for flex and rubber mounting ..
it's also super convenient during production ..
the just build 'the engine unit' fully assembled, and pop it into the car.
( or often, engine and trans assebled together first , then pop that
in. )
The stock Diesel Vanagon has *nothing* wrong with it ..
the only thing 'wrong' with it is people don't know to maintain the
rubber mounts..
exhaust shops generally are not that smart ..
so they get hacked up ..
As I have said many times ...the first time I saw the angles that the
left two rubber mounts are mounted at, I could tell someone was thinking
...some engineer ...one is mounted vertically ..(absorbs vibes
left-right ..holds weight in sheer ) ..
the other holds weight more in vertical load ..
but it's at 45 degrees....there had to be a real reason for that.
stock DV exhasut systems seldom crack ...
if they do it's due to letting them go when things are tired ...
the turbo exhaust systems I make that are a total copy, though bigger in
diameter last just fine.
regarding conversion exhasut system for inline four engines in the back
of vanagons ..
if they produce the result ...fine ....
that's nicely made, well supported, lasts really well, doesn't drone or
vibrate etc.
I have seen a TDI exhaust system ( engine at 50 degrees ) ..
had a normal flange and down pipe..
then a flex joint...
then ...the largish muffler was hung across the back by rubber donuts ...
Jetta spriney exhaust clamps were welded to the body to hang the rubber
donuts from.
Of course....the metal wasn't painted to prevent rust where the welding
was.
I get the impression I am the only engine coversion person that really
works on rust and preventiong.
I just 'could not' send out an engine conversion with raw unpainted
metal on it anywhere..
yet I see it commonly
Anyway ..at the end of the muffler which just sort of hung loosly across
the back was a big dick dong of a tail pipe sticking nearly straight
down ...on effort to tuck it into the corner just below the muffler.
I suspect many people don't realize that thereason the have the tail
pipe right at the corner of the body ..or close too is ...
a vortex of air there pulls the exhaust way from the back of the van -a
safey issue.
However ..looking at how the exhasut system was doneon that tdi ..
I could see that it wasn't going to crack or hurt itself in any way,
I also though the guy who built it spent like 40 minutes on it, and I
spend hours making mine.
So I did think ..
'for the effort involved' it was going to be durable and trouble-free..
just not elegant or really finished up right in my book.
Liketo shops weld brackets to vanagon badies to hold stuff..
like exhaust pipes or coolant pipes and then not even paint the bare
metal at the welded area .. ??
yes they do , sad to say. I see it commonly.
re tail pipe location ...
You want it tucked up in there some. If you ever back up into a berm of
dirt say ...shutoff the engine ..
and jam a bunch of dirt into the tail pipe ....
things might not act normal after that..and it may not be obvious why.
I will comment that the stock Tiico exhaustinstallation when Igot my
stock blown up Tiico , looks pretty funky/sloppy to me.
They kept the waterboxer trans location in the body ..( that puts the
bell housing face two inches further aft than an 82 DV has ) ..
and then the thickness of an adapter plate was added to that..
so on my 91 tiico ...
the muffler was almost jammed between the body and the engine ..
with no muffler heat shield either.
but my standards ..pure crap.
Since the shift linkage on my was very very stiff and barely working ..
I will be shortening the front manual trans mount by two inches..
thus getting a 'proper' two inches more at the back of the engine.
And I'll shorten the shift linakge to match.
Bottom line though ..
does it last well, doesn't crack or drone/resonate
and things are treated to prevent rust anywhere associated with the
installtion .
than it's pretty decent.
I wonder if anyone else paints their exhaust pipes and mufflers.
I never see anything on vanagons except rusty exhaust pipes.
If they are painted first with Flame Proof primer ..
then the final coat .I use light gray ..
they stay that way for quitea good while, and are easy to touch up in place.
there really is not reason for rust on a vanagon anywhere, not really .
Very rewarding to treat and prevent. And super easy. I *love* Zero Rust
spray paint ..
the very best paint in a spray can I everever found in decades ..
and I own about 100 cans of spray paint ..I am such a nut about
preventing corrosion.
it WILL last forever if actuallytaken care of-your Vanagon.
Scott
www.turbovans.com
On 12/20/2012 4:33 PM, neil n wrote:
> Hi all.
>
> Did VW mount the diesel exhaust to the engine *mainly* to reduce
> transmitting engine noise to the vehicle body?
>
> i.e. why didn't they use a flex joint and hang the exhaust from the
> body with rubber isolators?
>
> (this Foreign Auto Supply kit should show what I mean):
>
> http://www.foreignautosupply.com/parts-accessories/7-exhaust-down-pipe-hanger-kit-2lr-tiico-vanagon-engine-conversion/#.UNOq0I6thoA
>
> Or was this done mainly to prevent the exhaust from cracking?
>
> Comparing a gas to diesel is "apples to oranges" but understanding why
> VW designed the diesel exhaust the way they did, will help me decide
> which approach use for the new exhaust on my I4 swap.
>
> I'm sorry if this ends up being a cross post but felt it ok to ask the DV list.
>
> Thanks
>
> Neil.
>
>
> --
> Neil n
>
> 65 kb image Myford Ready For Assembly http://tinyurl.com/64sx4rp
>
> '88 Slate Blue Westy to be named.
>
> '81 VanaJetta 2.0 "Jaco" http://tubaneil.googlepages.com/
>
> Vanagon VAG Gas I4/VR Swap Google Group:
>
> http://groups.google.com/group/vanagons-with-vw-inline-4-cylinder-gas-engines
>
