[DeTomaso] aftermarket heat-A/C unit

[John Taphorn]

Matt

Kirk apprised me that he has had limited success mounting the condenser up 
front.  I recall his main issue is that the close proximity of the condenser 
to the radiator allows the heat from the radiator to warm the condenser.  At 
low speeds when the air flow through the units' is less, the condenser's 
effectiveness was compromised.

His best success came with running two condensers in series; one in the 
stock position and a second one with a shroud and suction fan in front of 
the passenger rear wheel behind a louvered splash guard.

I considered this approach quite seriously on Bill Lewis's car that I am 
presently restoring. However, I choose the path that all modern cars employ; 
placing the condenser in front of the radiator.

My plan to improve the airflow situation at low speeds is to utilize a 4 fan 
scenario.  Two pullers and two pushers.  Perhaps a configuration many may 
consider overkill; although, we are talking Texas heat and humidity.

We are also using the modified evaporator with 4 rows for R-134 and only 2 
rows for coolant.  The stock unit is 3 x 3 rows. Also incorporated is an 
expansion valve suited for R-134. The new single row condenser is as wide 
and tall as the new Quella Aluminum radiator.  Now that the radiator only 
sees air post condenser, the thought was to optimize the cooling system's 
efficiency. I approached this by improving coolant flow via removal of the 
swirl tank, moving the pressure cap to the low pressure side of the system 
mounted on a fill tank, and incorporating a remote thermostat.

The space up front is extremely tight when you are adding a condenser 
(however thin) to a thick aluminum radiator. The condenser needs to be at 
least 3/16" from the radiator and Bill's is about 1/2".  The largest 
practical fan size on the front is 10". This limitation is due to the front 
valence that the radiator sits down inside - the front fans will not fit 
down in the valence as well.. These are SPAL fans and we have a pair of 14" 
fans shrouded on the rear of the radiator.

Up for debate is that Quella supports the idea of a shroud to hold the front 
two 10" fans.  This shroud covers the front of the condenser entirely above 
the valence opening.  The valence opening is unshrouded.  Dennis and I 
disagree here and I am mounting the front fans w/o the shroud.  There are 
many pros and cons to each approach.  Clearly, the front shroud would 
enhance air flow when the car is stationary or barely moving to generate 
adequate airflow.  However, I opine the car will see stationary conditions a 
smaller percentage of time than when in motion.  Ideally, I am incorporating 
adequate airflow with the additional fans to provide adequate airflow when 
the Pantera is stationary. Again, the rear of the radiator is completely 
shrouded.

I plan to use a trinary switch that will act as a safety on the compressor 
and also start all four fans when AC system pressures are high.  In 
addition, the rear radiator fans will also come on at 190 degrees coolant 
temp (sensor in radiator) and the front pusher fans from a separate switch 
in the manifold (Windsor motor) ~196 degrees.  I am employing a thermostat 
that opens the cooling system at 187 degrees and I do not want the fans 
running at highway speeds, when adequate airflow can maintain system temp at 
187, unless pressures in the AC system require it.

I am figuring out how to run the AC lines this weekend.  I appreciated the 
comments by others on this topic a few weeks back.  I was intrigued with 
Jack's suggestion about placing the dryer in the front boot.  However, there 
appear to be to many compromises in light of other modifications, that I am 
making including, electrical to that scenario.  I hope to figure that out 
today.

We will see how this all works out.  Aside from efforts by Ken Green, Kirby 
Schrader and others to incorporate an electric water pump, I believe we are 
optimizing the cooling / AC application.  Ideally, our real world results 
will meet my, or rather Bill's, expectations.

I welcome your suggestions.  I had shoulder surgery last week and have 
limited mobility for a while.  Thus, my progress on Bill's car has slowed 
and I've got time to tune the approach.

JT




----- Original Message ----- 
From: "Matt" <matt at nwpantera.com>
To: "John Taphorn" <jtaphorn at kingwoodcable.com>
Cc: <detomaso at realbig.com>
Sent: Friday, February 12, 2010 10:42 PM
Subject: Re: [DeTomaso] aftermarket heat-A/C unit


> Thank you John. I guess Kirk has been around a Pantera or two! Like to see 
> what he has to say about the idea.
> Kirk? You around?
>
> Matt
> 3584
> ----- Original Message ----- 
> From: "John Taphorn" <jtaphorn at kingwoodcable.com>
> To: "Matt" <matt at nwpantera.com>; <JDeRyke at aol.com>
> Cc: <detomaso at realbig.com>
> Sent: Friday, February 12, 2010 8:12 PM
> Subject: Re: [DeTomaso] aftermarket heat-A/C unit
>
>
>>> I did notice one of the vendors mentioned a condensor mounted in the 
>>> right wheel well.
>>> Have you ,or anyone done this? I've heard of oil coolers before but not 
>>> the A/C.
>>> Seems doable but besides being hidden and slightly cooler air than the 
>>> back,I see no advantage,only negatives(dirt,grime,crap getting thrown up 
>>> into it, accessibility)
>>> Any thoughts?
>>
>> Kirk Evans is an advocate of this approach.
>>
>> JT
>>
>