NC hybrid setup/coolant blows heater core/how to avoid?

[thergen at svn.net]

I don't know if it's the same one as used on the gn, but take a look at gm
part #14044414.  It has four ports.  Normally, without vacuum applied, is
allows coolant to flow through the heater core.  With vacuum applied, it
bypasses the core and routes the coolant back to the engine.  It's usually
actuated when the a/c is in the max position.  The valve does not seal
perfectly, and some coolant does go to the core in closed position.

However, I think you could loosen the screw that holds the lever arm onto
the rotating part of the valve and just rotate the valve piece 90 degress
such that it is "open" (coolant goes through core) under vacuum and
"closed" without vacuum. I don't think there was any keying between the
lever are and the valve piece that would prevent this (take a look before
you buy).  Connecting it to manifold vacuum may then make it do what you
want.  Make sure the valve is installed such that is routes coolant back
to the motor when "closed" and doesn't simply cut off the coolant flow. 

Of course, the restrictors would be cheaper.

Tom

On Sat, 1 May 1999, Ross Corrigan wrote:

> At 01:29 PM 5/1/99 -0400, you wrote:
>   If you want really good control over the
> >heater coolant, use a heater valve off a 87 Buick GN/Ttype, it's vacuum
> >applied, On, type.
> 
> don't follow this too well, this is an inline valve in the heater supply
> line?  vacuum applied but what triggers the application of the vaccuum? an
> electric switch?  or do you mean at high vaccuum (low rpm's/throttle) it's
> open and it closes under WOT? off of manifold vaccuum?  That would be slick
> as well.
>