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Another fan clutch option, ElectroMag type.

The simplest way to control the elctric fans or electric clutch for A/C would be a thermistatic switch hooked to the condenser liquid line(the line coming from the condenser to the evap). Use one of the probes that you can put on the outside of the line, and set it to turn on around 140-150 degrees. When moving down the road and airflow picks up it will cool the condenser and shut off the fan when the liquid cools down, and then turn it back on when it heats up. Otherwise you would have to add in a high pressure switch somewhere, and set it to turn the fans on around 225-235 PSI high side pressure.
 
The above numbers is what I didn't know offhand. Thx Ferm!

I have never gotten electric fans to deliver enough CFM for the AC at idle on our trucks. (Experimented with a 1993 4.3 V6 1500) Many have tried on Trailblazers and failed. AC warms up at idle in traffic. Even tried a noisy flex fan and the engine warmed up at idle. Then burned up a twin fan electric fan kit for a 1995 Yukon...

The best combo I ever found was using a electric pusher fan strapped to the condenser along with the thermal clutch fan. (Aside of other mechanical clutch fan control schemes.) (Tested on 1995 Yukon. And for that year w/o rear AC the AC still sucked out here.)

Even police cruisers went to extremes to drive a mechanical fan off a FWD engine. After all the clutch fan is the biggest fan on the engine. For lesser climates like Michigan where the factory AC engineers appear to live and test maybe a electric fan alone will work...

Seriously modern AC systems are a lot better and more efficient allowing electric fans to do the job. Our systems on our trucks are not in that class - 1995 and older using 1970's compressor designs that sucked for R-12 let alone 134A.
 
I'm drooling. The thought of being done with this guessing game on fan clutches is making me giddy. Please remember to put me on the list for your grand debut
 
The above numbers is what I didn't know offhand. Thx Ferm!

I have never gotten electric fans to deliver enough CFM for the AC at idle on our trucks. (Experimented with a 1993 4.3 V6 1500) Many have tried on Trailblazers and failed. AC warms up at idle in traffic. Even tried a noisy flex fan and the engine warmed up at idle. Then burned up a twin fan electric fan kit for a 1995 Yukon...

The best combo I ever found was using a electric pusher fan strapped to the condenser along with the thermal clutch fan. (Aside of other mechanical clutch fan control schemes.) (Tested on 1995 Yukon. And for that year w/o rear AC the AC still sucked out here.)

Even police cruisers went to extremes to drive a mechanical fan off a FWD engine. After all the clutch fan is the biggest fan on the engine. For lesser climates like Michigan where the factory AC engineers appear to live and test maybe a electric fan alone will work...

Seriously modern AC systems are a lot better and more efficient allowing electric fans to do the job. Our systems on our trucks are not in that class - 1995 and older using 1970's compressor designs that sucked for R-12 let alone 134A.


So what would it take to retrofit our vehicles with a modern AC system?
 
So what would it take to retrofit our vehicles with a modern AC system?

Honestly this thread is part 1 of 2 - getting some air moving across the hot condenser that the obsolete spring thermal design doesn't do when needed. Also would help to get the oil coolers behind the condenser to help cool the condenser as much as possible.

Part 2 is a modern compressor:
http://www.classicindustries.com/product/truck/parts/346002.html

Complete under hood kit:

http://www.classicautoair.com/GM_OEM_Parts_Engine.html

Optional Part 3
VOV, variable Orface valve or TXV of some sort. Can't do on dual air systems.

Since we are experimenting:
Where not outright banned by law like it is in AZ: Alternate refrigerants like propane.
Seriously it's cheaper and flammable is no longer a concern with R1234yf being approved. :smuggrin:

Daimler bashed the environmentally friendly coolant with a shocking video, made public by Germany's Autobild. The video shows a coolant leak exploding into flames on contact with hot surfaces under the engine hood.
http://www.autobild.de/videos/video-killer-kaeltemittel-3706106.html

http://www.treehugger.com/cars/honeywell-defends-r1234yf-refrigerant-against-daimler.html

You sure you want a completely modern AC system? If I were to build one I would use a A-6 compressor with R12. 2nd choice use an expansion valve rather than the Orface tube system.
 
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Honestly this thread is part 1 of 2 - getting some air moving across the hot condenser that the obsolete spring thermal design doesn't do when needed. Also would help to get the oil coolers behind the condenser to help cool the condenser as much as possible.

Part 2 is a modern compressor:
http://www.classicindustries.com/product/truck/parts/346002.html

Complete under hood kit:

http://www.classicautoair.com/GM_OEM_Parts_Engine.html

Optional Part 3
VOV, variable Orface valve or TXV of some sort. Can't do on dual air systems.

Since we are experimenting:
Where not outright banned by law like it is in AZ: Alternate refrigerants like propane.
Seriously it's cheaper and flammable is no longer a concern with R1234yf being approved. :smuggrin:

Daimler bashed the environmentally friendly coolant with a shocking video, made public by Germany's Autobild. The video shows a coolant leak exploding into flames on contact with hot surfaces under the engine hood.
http://www.autobild.de/videos/video-killer-kaeltemittel-3706106.html

http://www.treehugger.com/cars/honeywell-defends-r1234yf-refrigerant-against-daimler.html

You sure you want a completely modern AC system? If I were to build one I would use a A-6 compressor with R12. 2nd choice use an expansion valve rather than the Orface tube system.

Isobutane and propane are perhaps the best freon replacements and have become very popular globally and low environment impact too while there is danger everywhere under the hood/bonnet and auto fire suppression system becomes a good idea too.

However too much isobutane and things begin to freeze in AC system.
 
Once you can get dimensions on this, you may find it will also work on the DURAMAX. 01-05 DURAMAX's use a fan clutch that is identical in dimensions to the late 99+ 6.5's spin on fan clutch. So your market for this may be alot more than just 6.5's as quite a few DURAMAX guys have swapped to electric fans to reduce parasitic load on the engine, but have found they can't tow with them as they don't move enough air. This setup would move the air when needed, but have no drag when not needed. The key is though getting the mounting depth of the fan and overall height so that it will work as the DURAMAX has very little clearance between the fan and radiator.
 
Ferm, its 4 1/2" from pulley face to the edge of fan closest to rad. This is on the four bolt flange.
On the screw on it may be different though. I'll be working hard on this when I get back in town toward end of June (2 weeks).

I have a couple other products soon to be released I know you guys will like.
 
Yes, its still very much on the burner. I have the machinist doing a couple things then I'll be on to this project again.
 
Just seeing this thread. Nice work Leroy, thanks for giving us products nobody else provides.
 
I meant for myself.

I still think he should put together a complete timing gear, 00 water pump, fan clutch, and duramax fan kit with all gaskets and crank seal. It's the perfect time to do all of that.
 
dont forget the fluidampr! :) I am stockpiling parts to just that, gears, FD, 00 WP, etc.

Due to time constraints, I have a stock damper on order to get the truck on the road until I can find time to tear into the front end of the engine, good shakedown run to make sure the truck is solid.


On cheaper local trucks I think I will be running stock fan and clutch for 99.5-00, but for the road pickups I would be excited to try the new electric clutch and a duramax fan.
 
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