Question of cooling system design theory,I-5 engine

Tue Apr 12 12:20:34 PDT 2011

That is a thing of beauty, and just what I need. My car does use cables for
the controls. However, the recirc flap is required for the AC to work in my
car. It is pooersted by an electric solonoid that controls vacuum to the
flap actuator. I'll "T" off that, and run it to the valve.

Thanks!!!
Tony

On Tue, Apr 12, 2011 at 2:07 PM, Cody Forbes <cody at 5000tq.com> wrote:

> Here is an example of the valve I'm thinking of:
>
> http://cgi.ebay.com.au/Heater-Valve-Tap-Holden-V6-Ute-Statesman-Monaro-1991-06_W0QQitemZ130491090171QQihZ003QQcategoryZ33548QQcmdZViewItem
>
> I google imaged "GM four way heater valve" and got a bunch of hits. Looks
> like it is vacuum controled, so it will go right in to most Audi's as long
> as you don't have the old/base model A/C panel with cables.
>
>
> http://www.ls1tech.com/forums/conversions-hybrids/1319726-bypass-type-heater-valve.html
>
> In the above link the one shaped like an H is the one I've seen before.
>
> -Cody
>
> --------------------------------------------------
> From: "Cody Forbes" <cody at 5000tq.com>
> Sent: Tuesday, April 12, 2011 3:01 PM
> To: "Andrew Dickinson" <amdickinson at rogers.com>
> Cc: <quattro at audifans.com>
> Subject: Re: Question of cooling system design theory,I-5 engine
>
>
> I don't have anything too useful to add other than a note that GM made a
>> 4-way heater valve in the mid 90's used on the LT1/LT4 and LQ (truck)
>> equipped vehicles. Picture four hose fittings and a 2 way valve (forget if
>> it's cable or electric). In position one the coolant flow was routed through
>> the heater core and the bypass blocked. In position 2 the bypass is opened
>> and the heater flow is completely blocked off. Would be an elegant solution
>> to impliment.
>>
>> -Cody (mobile)
>>
>> On Apr 12, 2011, at 1:20 PM, Andrew Dickinson <amdickinson at rogers.com>
>> wrote:
>>
>> Hi Tony:
>>>
>>> I have experienced similar issues on the 5k/2c cars.  I have thought of
>>> installing a set of valves to (A) Isolate the heater core, and (B)
>>> connect a
>>> by-pass when the core is shut off.
>>>
>>> I have also pondered the constant flow.  I can't see a German engineer
>>> allowing
>>> hot to flow when it should not UNLESS the idea is to keep some small
>>> amount
>>> flowing to prevent corrosion.  I discounted that idea and actually plan
>>> to
>>> install the multi-valve set up.  I have even thought of ddraining the
>>> core
>>> during summer months but I am not sure that would be more or less
>>> beneficial.
>>>
>>> That's my $0.02.
>>>
>>> cheers;
>>>
>>> Andrew
>>>
>>>
>>>
>>> ________________________________
>>> From: Tony Hoffman <auditony at gmail.com>
>>> To: quattro at audifans.com
>>> Sent: Tue, April 12, 2011 1:02:26 PM
>>> Subject: Question of cooling system design theory,I-5 engine
>>>
>>> Fellow Q-heads,
>>>
>>> I have a question of theory as I'm working on the A/C system of my '86
>>> 4000
>>> Quattro.
>>>
>>> Firts, a little background. I live in Houston, where we already are
>>> seeing
>>> 90 degree highs :( So, since my A/C compressor dies at the end of last
>>> summer, I've decided to upgrade while I'm in there. I have installed the
>>> rotary compressor from a 90Q, which also requires the lines, brackets,
>>> and
>>> Oil filter adapter. All said and done, the system is putting out 44
>>> degrees
>>> from the vents at 80 degree outside temps. Pretty good, for what I've
>>> seen
>>> so far. I've never been able to get it below 40 with the old setup. If I
>>> had
>>> the old setup just as it is now(I'll go over those details in a minute)
>>> it
>>> would be putting out somewhere around 52-55 degrees. So, I'm pretty
>>> pleased.
>>>
>>> However, in every 4000Q I've owned or driven recently, even with the
>>> heater
>>> all the way off (verified under the hood against the stop) the heater
>>> never
>>> quits giving out slightly heated air. I've replaced the heater valve on
>>> several of them as well. This current one will be replaced, as I have a
>>> new
>>> one here, but hasn't yet.
>>>
>>> Looking at the coolant routing, it appears that the heater core runs are
>>> sort of a "bypass" of sorts for the thremostat. So, if that's the case,
>>> maybe it isn't designed to ever shut off completely?
>>>
>>> So, here's the question, if I completely shut off that coolant flow, does
>>> that create hot spots in the cooling system or engine. I really can't see
>>> how it could, but I want to make sure.
>>>
>>> With the old system, I did have a set of pinch pliers designed to stop
>>> flow
>>> through rubber lines when you are working on them. Examples would be when
>>> you take a fuel hose off the pump, but don't want to drain the tank. I
>>> did
>>> that all last year, as that was the only way to get the temp from the
>>> vents
>>> below about 55degrees on hot days. I did not experience any sort of
>>> overheating, nor was anything damaged that I know of. But, I've got a
>>> valve
>>> setup that I'll be adding to permenantly shut off the heat during the
>>> summers, and I just want to make sure I'm not going to stop the flow that
>>> may be engineered into the cooling system.
>>>
>>> As always, TIA,
>>> Tony Hoffman
>>> _______________________________________________
>>> quattro mailing list
>>> http://www.audifans.com/mailman/listinfo/quattro
>>> http://www.audifans.com/kb/List_information
>>> _______________________________________________
>>> quattro mailing list
>>> http://www.audifans.com/mailman/listinfo/quattro
>>> http://www.audifans.com/kb/List_information
>>>
>> _______________________________________________
>> quattro mailing list
>> http://www.audifans.com/mailman/listinfo/quattro
>> http://www.audifans.com/kb/List_information
>>
>> _______________________________________________
> quattro mailing list
> http://www.audifans.com/mailman/listinfo/quattro
> http://www.audifans.com/kb/List_information
>