Date: Fri, 22 Aug 2008 08:18:05 -0500
Reply-To: Jim Felder <jim.felder@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Jim Felder <jim.felder@GMAIL.COM>
Subject: Re: Wrap exhaust pipes with fiberglass?
In-Reply-To: <20fbe3b00808220533y3774e4b6sdc511094b7444247@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
All that business about losing compression after a long run, that's
mythbuster's stuff from the aircooled days. I don't know what the
expansion is on the iron cylinder of an aircooled under load compared
with the expansion of the aluminum piston, but I be there's not much
difference, and I bet that difference would easily be made up by a
good set of rings.
I think the topic of covering exhaust with insulator was covered
pretty well a couple of weeks back and the consensus was that it was
bad for the engine in general and bad for the life of the pipes in
particular. If you want to reduce the temps in the engine compartment,
use one or two of those electric fans that people used to mount atop
bug and bus engines to blow out air when the car is at idle or in slow
traffic after a hot run. Idling and after shutoff is when the temps
spike up back there.
Jim
On Fri, Aug 22, 2008 at 7:33 AM, Mark Hersh <cmwolfsburg@gmail.com> wrote:
> I was in Harbor Freight buying X-treme Tape (on sale for 3.99 USD till
> 8/25, BTW, save $1) and I mentioned to a guy in that aisle that it got
> high marks from folks on the Vanagon list serv.
>
> He said he used to own a Vanagon and said I can reduce heat in the
> engine compartment by 70% if I:
>
> Wrap the exhaust pipes (engine block to the cat) with fiberglass
> (using some kind of high-temp fiberglass stuff), securing with
> stainless steel wire, which in time will bond the whole shebang
> together. That helps to send the heat out the exhaust and, as the
> exhaust pipes will no longer act as radiators into the engine
> compartment, reduce engine overheating, heat stress on electrical
> components.
>
> I guess I can see the reduction of waste heat part in a general sense,
> but I am puzzled about the engine overheating part. I'd think that a
> properly running Vanagon's cooling system will keep the block and
> heads cool enough that the hot exhaust pipes won't add that much to
> their heat load...
>
> He made a particular point about engine overheating, saying, after a
> long trip, you slow down, engine overheats, you lose compression,
> etc... and that this will fix all that.
>
> My guess is that if that fixed or improved something for him, then he
> had something else wrong with his van. But I smiled and thanked him,
> as I wanted to beat the traffic home.
>
> Thoughts from the collective brain power of the list?
>
> Mark, "one week till road trip!"
>
> --
> 86 Campmobile Six-Seater "Monty"
>
> Black dogs are euthanized at a greater rate than other-colored dogs,
> regardless of temperament. Learn about Black Dog Syndrome at
> http://www.blackpearldogs.com/
>
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