Date:         Fri, 1 Sep 2000 10:35:23 -0700
Reply-To:     Daniel Schmitz <djs@GENE.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Daniel Schmitz <djs@GENE.COM>
Organization: Genentech, Inc.
Subject:      Re: difference between '85 and '87 spare tire
Comments: To: k1cajun@PIPELINE.COM
Content-Type: text/plain; charset=iso-8859-1

I could be wrong, but I understood that different hoses are needed for
alloy-equipped vans because the wider wheels necessitate an increase in
space for the spare tire area, and different hoses are needed to clear the
spare. I posted this question to the list myself a few months ago, and
that's the answer I got from most people.

I'm not sure it has much to do with the rolling resistance of the
205/70R14 vs narrower tires, although I'm sure there IS slightly more
rolling resistance. However, I have to think that the vanagon's cooling
system is efficient enough to remove the infinitesimal increase in heat
resulting from running the fatter tires, and that different hoses are used
solely because of space constraints.

But I could be wrong...

Dan



Dave L wrote:

> I'm skeptical that the hose difference has anything to do with
> increasing cooling capacity due to the larger tire size.  Certainly to
> make up for the extra room for the spare, though.
>
> The amount of fluid that can be pushed through a system is going to be
> limited by the narrowist part and the ability of the water pump.
> Unless there is a different radiator also, then the hose ends are
> still the same diameter.  If the diameter of the hoses is larger in
> their middles, then it's probably to compensate for the extra
> turbulence created by the extra bends in them.
>
> I'm not an engineer - would someone who has more technical knowledge
> of fluid mechanics care to comment ?  My knowledge is only intuitive
> based on kayaking whitewater rivers.  When the river bed narrows or
> bends, the same amount of water goes through, even if there is a wide
> calm section of river above.
>
> Mark Dorm <mark_hb@HOTMAIL.COM> wrote:
>
> > Wonder if this is playing a roll in why the 2.1's aren't going as
> > many miles as the 1.9's before need a full rebuild...... yes, no,
> > maybe???
> >
> > From: Robert Lilley <Wolfvan88@AOL.COM>
> >
> >> David,
> >> You will also need the front radiator hoses for the vans equipped
> >> with the larger 205x70x14Ħħtires.  The hoses are slightly larger to
> >> accommodate the increased demand on the engine with the wider tires
> >> (They take more power to push then the narrower tires and cause the
> >> engine to generate more heat so VW put in larger hoses for the
> >> radiator to flow more coolant. And the hoses are shaped differently
> >> to accommodate the increased distance the tire rest is from the
> >> top.