Did you have anything on here about your setup?
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Hummer Fan clutch setup
- Thread starter Chief915
- Start date
Did you have anything on here about your setup?
ak diesel driver
6.5 driver
Electric Fan clutch
So for those who want accurate fan clutch engagement this could be for you. I know on my 96 the fan clutch has never engaged the entire time I've owned it. Living in cooler climates does have it's advantages. I even tried modding the spring to no avail. This clutch will only work with the spin...
www.thetruckstop.us
ak diesel driver
6.5 driver
Not at the prices they were talking about. Too rich for me
Will L.
Well-Known Member
The debate for the hmmwv set up is the use of the 4 bolt waterpump if serpentine belt.
Hmmwvs have a much higher failure rate with serp than v belt due to the imbalance volume of coolant. Also why pickup 6.5s had so many issues and why gm kept changing the waterpump design.
I started trying to figure out spin on water pump with hmmwv fanclutch on serpentine belt- but life brought all my projects to a halt.
that said- Twisted Steel and a couple others says he had no issues of the unbalanced flow with the 4 bolt.
I know of hmmwvs that swapped from the hydro clutch to just thermal and blew engines in nearly no time.
Hmmwvs/ hummers have much worse air flow issues than any of the pick
That thread saying hmmwvs couldn’t control the fanclutch is right, sort of. The deep waterfording kit hmmwvs had a switch that disengaged the clutch to not brake the fan, along with other changes. Also some spec op hmmwvs had a switch to engauge or disengage the fan to help cool when hot, and turn off when max speed was needed- but that of course led to blown engines.
you can rig a switch to go on/auto/off if wanted.
The fact that it is rebuildable and is 100% lock up is awesome. But the set up AK did not loosing rpm like other thermal fan clutches do makes it might appealing. Both could be controlled to come on at any temp you choose. If the military learned to use a bigger turbo, they could have had fan come on earlier and not blown so many engines, but the power loss was too dramatic.
I have said for years and still do that whoever makes a working adapter for spin on water pump to hmmwv clutch can make descent cash selling just the adapter. A complete system of new parts is so expensive but selling parts for diy makes sense.
Hmmwvs have a much higher failure rate with serp than v belt due to the imbalance volume of coolant. Also why pickup 6.5s had so many issues and why gm kept changing the waterpump design.
I started trying to figure out spin on water pump with hmmwv fanclutch on serpentine belt- but life brought all my projects to a halt.
that said- Twisted Steel and a couple others says he had no issues of the unbalanced flow with the 4 bolt.
I know of hmmwvs that swapped from the hydro clutch to just thermal and blew engines in nearly no time.
Hmmwvs/ hummers have much worse air flow issues than any of the pick
That thread saying hmmwvs couldn’t control the fanclutch is right, sort of. The deep waterfording kit hmmwvs had a switch that disengaged the clutch to not brake the fan, along with other changes. Also some spec op hmmwvs had a switch to engauge or disengage the fan to help cool when hot, and turn off when max speed was needed- but that of course led to blown engines.
you can rig a switch to go on/auto/off if wanted.
The fact that it is rebuildable and is 100% lock up is awesome. But the set up AK did not loosing rpm like other thermal fan clutches do makes it might appealing. Both could be controlled to come on at any temp you choose. If the military learned to use a bigger turbo, they could have had fan come on earlier and not blown so many engines, but the power loss was too dramatic.
I have said for years and still do that whoever makes a working adapter for spin on water pump to hmmwv clutch can make descent cash selling just the adapter. A complete system of new parts is so expensive but selling parts for diy makes sense.
I have no trouble now with a four bolt pump and a single thermostat housing on my 1997 K2500. I'm just really liking the idea of no drag when the fan is disengaged. I once ran an old 6.2 all winter without a fan and it was surprising how much more power it had. Of course I had to turn it off if I had to stop for more than 15 or 20 seconds.
Will L.
Well-Known Member
There were a couple folks that mentioned the FlowKooler, but I hadn’t heard anyone with long term results. So is that what you have been using?
If you are happy your set up- then yeah the hmmwv clutch makes sense. Copy big blue.
I can’t remember if he added external controls, but I sure would. Instead of Temp sensor use electric fan controller and single pole triple throw switch so in auto the system runs automatically and you can adjust what temp it kicks in at. Then switch to ON for when you want to force cooling, and switch to OFF for deep water crossing if needed. Then a trinary switch from a/c so it can engage when you need it for better cooling of a/c like all other modern vehicles have. All those feed to a relay, then to the solenoid.
If you are happy your set up- then yeah the hmmwv clutch makes sense. Copy big blue.
I can’t remember if he added external controls, but I sure would. Instead of Temp sensor use electric fan controller and single pole triple throw switch so in auto the system runs automatically and you can adjust what temp it kicks in at. Then switch to ON for when you want to force cooling, and switch to OFF for deep water crossing if needed. Then a trinary switch from a/c so it can engage when you need it for better cooling of a/c like all other modern vehicles have. All those feed to a relay, then to the solenoid.
No, I haven't used a FlowKooler as of yet but the next time I need a pump that's what I'm going to get. I'm just using the latest 4 bolt water pump. I don't have any idea if I have balanced flow or not but I've never been able to overheat it even when towing a rock crawler through the mountains. I've only ever heard the stock clutch fan kick in a few times.
smokymtn65
Well-Known Member
You better hang on to that one! Or double check temp gauge or sensor! LOL
Will L.
Well-Known Member
Get an adjustable unit. You’re going to want to tweak it to your use. Start around 1 adjust from there.
Better to start low and waste a couple gallons of fuel than be too high and waste an engine.
Many engines do better mpg with 195, some don’t. 161 is warmed up with the 6.2/6.5. So anything above that is ok, and the hotter it gets the harder it is on everything. 180 is the most desirable number to me and most others in the southwest. But being able to kick it on full blast at anytime means you could run higher. But if you don’t see any mpg gains from
The higher temp- dumb to have there.
But since you are running the 4 bolt pump- get another gauge in the right rear head by the glowplug. That is your danger/ cracking head area.
The rule is 200 pay attention, 210 pay more attention to the gauge than the road, 220 pull over.
Adding in the switch that forces on is seriously an engine saving part. Definitely want that prior to test drive incase something goes wonky.
Please do pics and write up as you go. We all love to follow along and you might help others along the way, including me. You might do things the rest of us never thought of.
Better to start low and waste a couple gallons of fuel than be too high and waste an engine.
Many engines do better mpg with 195, some don’t. 161 is warmed up with the 6.2/6.5. So anything above that is ok, and the hotter it gets the harder it is on everything. 180 is the most desirable number to me and most others in the southwest. But being able to kick it on full blast at anytime means you could run higher. But if you don’t see any mpg gains from
The higher temp- dumb to have there.
But since you are running the 4 bolt pump- get another gauge in the right rear head by the glowplug. That is your danger/ cracking head area.
The rule is 200 pay attention, 210 pay more attention to the gauge than the road, 220 pull over.
Adding in the switch that forces on is seriously an engine saving part. Definitely want that prior to test drive incase something goes wonky.
Please do pics and write up as you go. We all love to follow along and you might help others along the way, including me. You might do things the rest of us never thought of.
I am really wanting to try for simple by using the on/off sensor instead of an adjustable electronic unit. I will definitely have a manual override switch inside. I'm also going to wire up a trinary switch for the A/C control. Everything does a fine job of cooling now I just thought the free wheel ability of this clutch would help with mileage and power. I'll do what I can with pictures but that's not my best area.
Will L.
Well-Known Member
In trying to get mileage, you want the fan to come on last minute. That means adjusting to it.
you can buy an assortment of temp switches. 180,185,190,195 and try them all. But the cost and lack of adjustment would make that not worth it to me. If you want to try it that way a 195 switch to match t stat makes sense but you aren’t leaving much room for error.
where you tap it in is going to affect it also. Thats why Reading REAL temp at worst location (right rear head) is important. If you put your switch on the crossover and it turns on when say 185 there, but rear of the head is at 210- your playing with fire.
Putting sensor right rear, but having a stat too high means fan will cool radiator with stat closed and you don’t realize why it’s taking a long time to bring down the temps.
Switch installed by thermostat so it cools only when stat opens up makes sense. But I think you are going to find faster cooling and that will mess with where it should happen at. So swapping temp switch a lot of times learning it will be required.
Also if you just drive it like a car often but then tow heavy- you might want to learn the two levels you need it at. Towing heavy will require sooner fan than just milk and bread runs.
you can buy an assortment of temp switches. 180,185,190,195 and try them all. But the cost and lack of adjustment would make that not worth it to me. If you want to try it that way a 195 switch to match t stat makes sense but you aren’t leaving much room for error.
where you tap it in is going to affect it also. Thats why Reading REAL temp at worst location (right rear head) is important. If you put your switch on the crossover and it turns on when say 185 there, but rear of the head is at 210- your playing with fire.
Putting sensor right rear, but having a stat too high means fan will cool radiator with stat closed and you don’t realize why it’s taking a long time to bring down the temps.
Switch installed by thermostat so it cools only when stat opens up makes sense. But I think you are going to find faster cooling and that will mess with where it should happen at. So swapping temp switch a lot of times learning it will be required.
Also if you just drive it like a car often but then tow heavy- you might want to learn the two levels you need it at. Towing heavy will require sooner fan than just milk and bread runs.
smokymtn65
Well-Known Member
I drilled and tapped my crossover for the sensor on mine. Not saying it's the right place, it has been working.
Twisted Steel Performance
Anything worth doing is worth overdoing.
Currently mine is in the d/s head at the front, but the hottest place is the p/s head at the rear..
I don't remember what on & off temp my controller is set at, but it's adjustable to whatever I chose..
I don't remember what on & off temp my controller is set at, but it's adjustable to whatever I chose..