Cooling system upgrades

[TexF18]

I upgraded the cooling fan

Heavy Duty Engine Cooling Kit (HMMWV Serpentine Belts) | WARTECH PERFORMANCE

Notice your HMMWV runs hot at 210-230F and saps the engine power when the fan engages? Upgrade your obsolete hydraulic fan setup with our modern thermostatic cooling kit. The stock HMMWV system was designed to run HOT to efficiently burn multi-fuel and JP8 (jet fuel). While this is fine for a...

www.wartechperformance.com

kit got temps down to 190-210. Question is should I also add on the paradox cooling kit.

Military HMMWV, HUMVEE Cooling Upgrade System

PARADOX HMMWV 6.2/6.5/6.5T COOLING UPGRADE KIT (patent pending)This is simply the best bang for the buck upgrade you can make to your truck, period! Must do before any performance or horsepower mods.All HMMWV HUMVEE trucks with GM Detroit Diesel V8 6.2/6.5/6.5T engines all share an inherent...

paradoxbydesign.com

 

[TOBASH]

Please fix your link. Comes up blank

 

[TexF18]

Please fix your link. Comes up blank

Fixed

 

[TOBASH]

Respectfully…

1-Military cooling upgrade kit requires pixie dust and Elvin magic. AMG woulda done it if it worked.

2-Unless your hydraulic system is missing or busted, nothing is wrong with the HMMWV cooling system as-is. That viscous system posted is only 80% maximal. Cannot lock up. It will work somewhat BUT it is not efficient. And that part about losing horsepower is bullcrap. You lose horsepower with either system!

Both topics have been discussed on this forum multiple times.

Caviat Emptor

 

[NDT]

AMG did put the viscous clutch on H1s, Tobash yours should have it.

 

[TOBASH]

Yes. And it is inferior to the HMMWV system. I own several HMMWV and I own my 1995 Hummer. I can say by experience that my HMMWV A0 through ECV REV A are universally superior. Temps when the fan is activated get lower in a flash. I can also use a switch to bypass the Cadillac valve to activate the unit at will. And military units run at 100% when locked up.

Happy Fathers’ Day.

 

[NDT]

What’s important to know about the viscous clutch is fording. With that clutch, if the engine is red hot after a highway run, fan fully engaged, and you enter deep water, all the blades will break off the fan, and puncture the radiator. This obviously is a show stopper to Uncle but maybe not you.

 

[Hummer Guy]

I upgraded the cooling fan

Heavy Duty Engine Cooling Kit (HMMWV Serpentine Belts) | WARTECH PERFORMANCE

Notice your HMMWV runs hot at 210-230F and saps the engine power when the fan engages? Upgrade your obsolete hydraulic fan setup with our modern thermostatic cooling kit. The stock HMMWV system was designed to run HOT to efficiently burn multi-fuel and JP8 (jet fuel). While this is fine for a...

www.wartechperformance.com

kit got temps down to 190-210. Question is should I also add on the paradox cooling kit.

Military HMMWV, HUMVEE Cooling Upgrade System

PARADOX HMMWV 6.2/6.5/6.5T COOLING UPGRADE KIT (patent pending)This is simply the best bang for the buck upgrade you can make to your truck, period! Must do before any performance or horsepower mods.All HMMWV HUMVEE trucks with GM Detroit Diesel V8 6.2/6.5/6.5T engines all share an inherent...

paradoxbydesign.com

Yea I have this same fan, for me it's much better than the original cadillac valve setup, especially going uphill. I know people say these engines can run hot, but these 6.5s are not no cummins or duramax, the 6.5s are well known for a high failure rate of overheating and crack blocks. I also feel a bit more comfortable with my engine staying in a more optimal temp range, instead constantly heating up to 230 and cooling back down to 180 every few minutes or so. As for the paradox cooling kit, I don't think its 100% necessary, I have it, but I never tested it or seen anyone else test it to actually see if it cools the rear cylinders better or possibly even create more hotspots in the engine.

In my opinion, just the fact of not having to worry about the fan leaking makes it worth it.

What’s important to know about the viscous clutch is fording. With that clutch, if the engine is red hot after a highway run, fan fully engaged, and you enter deep water, all the blades will break off the fan, and puncture the radiator. This obviously is a show stopper to Uncle but maybe not you.

It should still be able to ford water just like any other MV with a mechanical fan clutch system. Most likely if you ford water with your engine red hot, you'll probably risk damaging the block by such a hard temperature change. Most people break their blades by slamming their truck in the water at a high speed instead of slowly going in

 

[86humv]

AMG made a bunch of M11xx trucks for a desert overseas country that have the viscous system .

 

[REF]

I took off a perfectly functioning hydraulic fan clutch and installed a viscus clutch some time ago,
Why? although it is true that the hyd system locks up 100 % and the viscus system only 80% the viscus system unlocks to 20% instead of 0% so there is always air flowing. It gets hot here not uncommon to see 104 to 108 deg for months on end and I didn't like the engine hitting 220 to 230 the fan kicks on and cools it down to 180 to 190 then back up to 230 over and over again all day long. Now with the viscus clutch my temp gauge sits right at 190 all day in 104 temps (using the factory temp gauge).
So I like the viscus system, Don't Know that I needed it but I like it. I also run the paradox system, don't know if it helps but I feel that anything that helps trapped air or steam out of the back of the engine can't be a bad thing.
Maybe a little all the time works better than a lot all at once as far as air flow goes.
Note: when looking at a viscus fan clutch heavy or severe duty clutches have 80% locked and 20% unlocked some std duty clutches may unlock completely.

 

[twisted60]

Any part numbers on fan clutch ? Were you able to reuse your original fan ?
Thanks

 

[REF]

this was pretty strait forward, could not use my original fan and you will have to cut down the replacement fan.


Use a Hayden Fan Clutch P/N 2839 or USMW fan clutch P/N 22613 (Cheaper option)
For the Fan AC Delco P/N 15010202 or Dorman P/N 621-514 (cheaper option) same fan.

I did trim leading edge and top back for clearance to shroud original fan 19.5” these fans are 20.8”for duramax, 2500,3500 trucks.

Take the face of your factory HMMWV water pump pulley and grind or machine the face of it flat, there is a rise in the middle of the face that indexes the hyd clutch that needs to come off.
Now to index your new thermal clutch, It is set up for a 3/4 inch pilot so if you take a 3/4" bolt and cut approx 3/4" of the smooth shank (no threads) off that will fit into your clutch pilot perfectly and effectively turn your female 3/4" pilot into a male pilot out of the clutch. After you have machined your factory pulley flat, measure the depth of the 3/4” female pilot on the pulley with it installed and trim the male pilot on the clutch to that length. The 4 bolts that hold the pulley to the water pump is the same bolt pattern as the clutch and you could put longer bolts in and secure the whole thing that way, but I prefer to clock the clutch mounting flange 90 deg and drill and tap 4 new holes for the clutch to pulley mount and install studs. If you want to keep it looking original the 4 holes would be 8MM x 1.25 thread and 30 MM studs same thread pitch with self locking nuts.

This keeps pulley alignment, belts and everything else original and allows you to get rid of the hyd system.


If you want to go one step further you can replace the water pump with a FlowKooler high performance high volume pump P/N 1677 flat hub (direct replacement). These are made in Paso Robles Ca. check out their web site.

Yes with this setup the fan runs at 20 % lockup all the time and 80% when warm but on my M1123 the system runs cool and steady on the 195 thermostat and you can occasionally hear the fan speed up but is still a lot quieter than the hyd set up and I don’t have the temp cycling up to 220+ then down to 190 continuously.

Fan and clutch from RockAuto.com
Tap and studs from Amazon

Hope this helps