[DeTomaso] Pantera AC upgrade

Sat Jul 16 21:00:18 EDT 2011

Boyd

1) I have been informed in the past that even the 508 is a little too much 
capacity for the Pantera's system.  If so, the 709 may be problematic.  I 
believe the source of this data was the book on AC Systems written by the 
owner of Vintage Air and he cautioned about too much compressor.

2) After talking with many of the AC vendors, I have concluded that with the 
exception of flare vs. o-ring fittings, there is not a meaningful difference 
in R-12 vs 134A expansion valves.  I'd clean out the screen in the one you 
have and reuse; especially, if you are keeping your original evaporator that 
has a flare fitting.

3) I can't say enough about the quality and ease of use & installation of 
the new Aeroquip EZ-Clip lines and fittings.  I doubt they would blow.  Can 
buy inexpensively at Aeroquip.cc

4) I have used a Diesel Kiki compressor that was sold through Quella.  Good 
results with it.  I do not know it's RPM limit.

Share your results

JT

----- Original Message ----- 
From: "boyd casey" <boyd411 at gmail.com>
To: "De Tomaso List" <detomaso at realbig.com>
Sent: Saturday, July 16, 2011 4:16 PM
Subject: [DeTomaso] Pantera AC upgrade

> After doing some research and asking for the help and opinions of our
> brother hood I have found devised an updated AC system that does not 
> require
> moving the condenser to the the front of the car  and promises to improve 
> to
> some extent  the cooling capacity of the pantera with R134 and the common
> conversion from the york compressor to the Sanden 508.
> My preliminary research into the problems with the accepted upgrade of the
> York compressor to the Sanden 508 revealed several problems and faults 
> with
> both the original system and the upgraded system.
> *1*.. Neither the York nor the Sandeen  came with a high / low pressure 
> cut
> off switch. This issue was further exasberated when the upgrade / 
> conversion
> included the switch from R12 to R 134. The R 134 operates at a much higher
> pressure and and when  over pressure  situation occurs  ( which is
> apparently not uncommon while using R 134) it causes the AC hoses to be
> blown off at their weakest points which can necessitate the replacement of
> the AC hoses running from the compressor to the heater core under the dash
> board which on early cars (1972 and before) run through the rocker boxes 
> and
> are a major PIA to replace. The stock dryer does not have a port to 
> install
> the High / low cut off switch. You can purchase a dryer with a port that
> allows the installation of the high /low pressure cutoff switch for $14.99
> (or $40.00 if you want the bling of chrome plating) The switch is the 
> wired
> in series with the rotary switch on the dash board and will shut down the 
> AC
> compressor if either an over pressure or low pressure condition exist. The
> Hi/ low switch is available for $9.99 and $5.99 for the plug and pigtail.
> *2.* The next change to the normal upgrade process is the replacement of 
> the
> stock condenser fan with a high powered sucker fan. Procomp makes a 
> variety
> of fans that combine  high CFM with a low amp draw which when combined
> increase the cooling capacity of the condenser. I found a 10" Pro comp fan
> that is rated at 1000 CFM and is Chrome Plated ( is you are looking to 
> dress
> up your engine compartment  for only $29.99 plus $8.00 shipping.) I also
> found one in black for $17.00 and $10.00 shipping. These are supposed be
> made to fit with out to much difficulty.
> *3.* If you really want to improve  the cooling capacity and overcome some
> of the difficulties faced by operating the condenser at the back of the 
> car
> the best solution (without moving the condensor to the front of the car is
> to go with a parallel flow condenser. They are available in a variety of
> different sizes and configurations and prices. The one I found and have
> decided to go with is available from Nostalgic Air. It is a unit that
> combines a parallel flow condenser two 12" fans and a polished aluminum
> shroud all for only $239.99 the two fans move 1900 CFM  (950 cfm each fan)
> and the draw 8 amps per fan (16Amps total)
> The basic info is as follows :
>
> Condenser core size: 14" x 25"
> Overall condenser size: 14-1/2" tall x 27" wide
> Overall thickness: 3-1/8"
> Fan CFM (per fan): 950 CFM
> Total CFM: 1900 CFM (both fans mounted on condenser w/ shroud)
> Amps: (per fan) 8.0 amp draw
> Total amps: (16.0 amp draw (both fans mounted on condenser w/ shroud)
>
> Condenser with shroud and dual fans
> $239.99<http://condenser%20with%20shroud%20and%20dual%20fans%20$239.99/>
>
> After considering the costs of condensers ,fans  , and the fact that  a 
> self
> fabricated set up would not include a shroud for $239.99 I felt this was 
> the
> way to go.
>
> *4.* The single most important and expensive item is the condenser. After
> researching the sanden web sight I wondered why no one had ever used a
> compressor besides the  Sanden 508. I had written a post a few days ago
> asking if anyone knew why the Sanden was referred to as a "Rotary"
> compressor since it is piston operated and not rotary. No one supplied an
> answer. After speaking to some air conditioning people I decided to go 
> with
> a sanden 709 instead of the 508.
>
> The 508 has 5 pistons and 138cc ,8.39 C.I.D.  displacement ,the 709 has 7
> pistons and 154cc ,9.36 C.I.D. t They both have the same external 
> dimensions
> and mounting dimensions.
>
> The 508 has a max operating rpm of 5K and the 709 has a max rpm of 6K.
>
> Having a compressor with a higher displacement,and or operating speed is 
> not
> in it's self enough to necessarily increase the cooling capacity. Since I 
> am
> also going with a more efficient as well as larger condenser that is also
> incorporating two fans  these factors combined with the higher capacity
> compressor should work together  to help over come the less efficient
> cooling capacity of R134 and the handicap of a rear mounted condenser.
>
>
>
> The condenser, dryer and compressor can all be used with R12 or R 134. I
> have some R12 left. I have not decided whether to go with R12 or switch 
> over
> to R 134 If I charge the system with R12 and then decide to switch to R 
> 134
> I will have to completely flush and clean the system as well as change the
> Dryer again.
>
> I don't know if I am going to have to replace the expansion valve. I have
> read that it is a good idea to replace it when you have the system
> evacuated.
>
> This is my plan for upgrading my ac system. If anyone notices an obvious
> error or something I may have overlooked please let me know what it is. I 
> am
> no AC expert and this is my own plan for upgrading my AC system. If it 
> works
> well I will share the results with the list. If it doesn't I will chalk up
> another one to learning the hard way.
>
> Boyd
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