I have always been a bit wary about completely shutting off flow through the
core for months at a time... it seems to me this might increase the risk of
corrosion in the heater core, and this is a NLA part that is a PITA to
change.

On Fri, Jun 24, 2011 at 2:34 PM, Dave Mcneely <mcneely4@cox.net> wrote:

> the heater cores do extract heat from the coolant, and that effect can be
> taken advantage of to help cool the engine (of most vehicles) in the event
> of overheating.  However, it typically is not necessary, or there would be
> no heater shutoff valve.  If it were necessary, driving any vehicle in
> summer would be a "roast."
>
> mcneely
>
> ---- "Nirav V. Patel [USA]" <goodbhai@GMAIL.COM> wrote:
> > Are the heater cores part of the system to extract heat from coolant?  Is
> is
> > a necessary step in the coolant system?  Or maybe that thought
> > is negligible?
> >
> > +nirav
> >
> > On Fri, Jun 24, 2011 at 10:33 AM, Jake de Villiers <
> > crescentbeachguitar@gmail.com> wrote:
> >
> > > Why not just solder two 2 1/2" long 1/2" copper stubs into a 1/2" ball
> > > valve
> > > and stick that in there?  1/2" copper fits inside that 5/8" heater hose
> > > very
> > > well.  Add a couple of clamps and you're good to go!  ;)
> > >
> > > On Fri, Jun 24, 2011 at 6:54 AM, Edward Maglott <emaglott3@gmail.com>
> > > wrote:
> > >
> > > > John,
> > > > I have installed a prototype valve that shuts off all flow to both
> > > > heaters in my 2.1.  It is installed in the heater hose near the
> > > > driver's side driveshaft.  I made it out of CPVC because it was
> > > > cheap.  I know that material is not compatible with the coolant, I
> > > > will take it out promptly.  Probably will make the final version out
> > > > of copper unless someone points me to a better choice at a similar
> > > > price.  I used a 1/2' ball valve with about 3" of 1/2" pipe sticking
> > > > out of each end.  Cut the hose and stuck the pipes into each end and
> > > > secured with 2 hose clamps on each.  Works great.  You do have to get
> > > > under the van to switch it on or off, but for the really hot part of
> > > > the year that is probably fine.  It is pretty easy to reach and do
> > > > without getting dirty if you lay down your piece of cardboard or tarp
> > > > that lives between rear cushion and engine cover.
> > > >
> > > > Neither of my heaters turn off completely.  I don't notice it until
> > > > it is really hot.  Even though there is no air moving past the rear
> > > > heater it heats up the whole underseat cabinet and bed area if I
> > > > drive  a few hours.  Not cool for sleeping.
> > > >
> > > > Edward
> > > >
> > > >
> > > > At 07:46 AM 6/24/2011, John Rodgers wrote:
> > > >
> > > >>  I need to install a summer shutoff valve on the hose to the front
> > > >> heater core. I just cannot get the heat valve to close tight enough,
> and
> > > >> in this summer heat hot air blowing is a bit much. Is this procedure
> > > >> posted on a website anywhere? Got a link?
> > > >>
> > > >> Thanks,
> > > >>
> > > >> John
> > > >>
> > > >> --
> > > >> John Rodgers
> > > >> Clayartist and Moldmaker
> > > >> 88'GL VW Bus Driver
> > > >> Chelsea, AL
> > > >> Http://www.moldhaus.com
> > > >>
> > > >
> > >
> > >
> > > --
> > > Jake
> > >
> > > 1984 Vanagon GL 1.9 WBX - 'The Grey Van'
> > > 1986 Westy Weekender/2.5 SOHC Subie - 'Dixie'
> > >
> > > Crescent Beach, BC
> > >
> > > www.thebassspa.com
> > > www.crescentbeachguitar.com
> > > http://subyjake.googlepages.com/mydixiedarlin%27
> > >
>
> --
> David McNeely
>