Hayden HD Clutch and HDS 203F Tstat

mass-hole · **Posted:** Fri Aug 05, 2016 12:20 pm

Is anyone running a Hayden 2905 fan clutch and the HDS tstat housing with 203 degree Hemi tstat? Based on what I have seen around here, the Hayden clutch engages at 170F air temps coming off the radiator, but seeing as I would now be running almost 30F hotter coolant temps then stock, is the fan clutch going to be engaged all of the time once the engine is up to temp?

I'd rather do an e-fan conversion but just dont know when I can get too it.

jws84_02 · **Posted:** Fri Aug 05, 2016 1:02 pm

According to Jeff's claims. You could prolly run without a fan if not doing heavy/extreme towing

mass-hole · **Posted:** Fri Aug 05, 2016 1:17 pm

jws84_02 wrote:

According to Jeff's claims. You could prolly run without a fan if not doing heavy/extreme towing

No towing, but I am already having overheating issues. I believe those are related to the fact that I have turned up boost and fueling and removed all the altitude related limiters. So I am already generating more heat than most and when combined with the fact that I live at 6500' its overwhelming the cooling system on long steep grades. I was actually wondering if it would work better if I removed the fan and fan shroud to open up the flow path through the radiator. Instead of having that big radiator area forced through the small fan opening, it would just be able to flow the full surface area of the radiator.

Obviously a fan would be a better but if I could save the money on the clutch and just get a electric fan down the road I think that would be better.

WWDiesel · **Posted:** Fri Aug 05, 2016 3:09 pm

Electric fans work, just how well as opposed to a good mechanical fan depends on the CFM being moved through the radiator! :juggle:

What fan blade are you running, the stock metal fan or a 11 blade plastic fan?

I swapped to the 11 blade GM fan and HD Hayden fan clutch to help get a little better cooling especially in stop and go traffic here on HOT Georgia days so the AC would work a little better and it seems to helped a good bit...

Bit it would work to help keep things cooler for your grade climbs?

GM Severe Duty Fan Clutch NAPA 271625
GM 11 blade HD Cooling Fan NAPA No. 8552223
Hayden Fan Clutch for GM is: HY 2986

mass-hole · **Posted:** Fri Aug 05, 2016 4:12 pm

WWDiesel wrote:

Electric fans work, just how well as opposed to a good mechanical fan depends on the CFM being moved through the radiator! :juggle:

What fan blade are you running, the stock metal fan or a 11 blade plastic fan?

I swapped to the 11 blade GM fan and HD Hayden fan clutch to help get a little better cooling especially in stop and go traffic here on HOT Georgia days so the AC would work a little better and it seems to helped a good bit...

Bit it would work to help keep things cooler for your grade climbs?

GM Severe Duty Fan Clutch NAPA 271625
GM 11 blade HD Cooling Fan NAPA No. 8552223
Hayden Fan Clutch for GM is: HY 2986

I am still on the stock fan and clutch. Do we know the rated flow on the 11 blade unit?

That's what I am not sure about. The thing is I am already running at 70 mph. It's a 3,000 foot climb from Salt lake to the top of parleys Canyon which I-80 runs up and I can pull the whole thing locked in 5th so I am only running at 2100 rpms or so. I figured the new clutch will at least make the fan spin so it's not just a restriction for the air trying to get out of the shroud. That's also why I am wondering if just removing the fan and shroud all together is the best idea since my issues have really only been at higher speeds and low rpm.

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f5hunter · **Joined:** Fri Jan 09, 2015 6:04 pm **Posts:** 45

I am running this combo (10,000 miles) with the 11 blade plastic fan. I have never heard/felt the Hayden engage although I haven't towed with this combo yet.

WWDiesel · **Posted:** Fri Aug 05, 2016 5:48 pm

mass-hole wrote:

That's what I am not sure about. The thing is I am already running at 70 mph. It's a 3,000 foot climb from Salt lake to the top of parleys Canyon which I-80 runs up and I can pull the whole thing locked in 5th so I am only running at 2100 rpms or so. I figured the new clutch will at least make the fan spin so it's not just a restriction for the air trying to get out of the shroud. That's also why I am wondering if just removing the fan and shroud all together is the best idea since my issues have really only been at higher speeds and low rpm.

I respectfully disagree on removing the fan shroud! Removing it will make the mechanical fan a lot less efficient when it is in service at correct speed. It is not that big of a shroud to start with and does not cover much if any of the backside of the radiator.
If your fan clutch is bad, it will not increase the fan speed as it should when the temperature loading starts. With the engine hot, turn engine off and try to spin fan by hand, it should be very hard to turn. If it spins freely, clutch is bad!

As to the 11 blade fan; yes 11 blades will move more volume of air as opposed to a stock 5 blade fan given they are the same diameter IMHO.... :wink:

The GM 11 blade fan / Hayden HD Clutch I choose does set a little closer to the motor which puts the fan right in line with the end of the shroud which I think makes it a better choice than the Mopar 11 blade fan....

Have you tried the old trick when pulling the grade and it starts heating up to cut off the AC, cut the heater on high (windows down of course) and see if that helps any with the heating up?
Are you running the correct antifreeze? And lastly have you tried adding some Red Line Water Wetter to the coolant to see if that helps any?

TURBO-DIESEL-FREAK · **Joined:** Sat Apr 17, 2010 3:29 pm **Posts:** 1167

jws84_02 wrote:

According to Jeff's claims. You could prolly run without a fan if not doing heavy/extreme towing

jws84_02:

Please do not speak or post on my behalf.

In situations like this I prefer to speak to my customer directly. Driving and environmental conditions vary so greatly that what works well for one CRD owner may not work at all for another.

mass-hole, please PM me with a telephone number and a time to call you, (I know I have your number, but it will save me looking it up). I am certain we can work out solutions that will give you additional peace of mind, and perhaps save you some fuel at the same time.

geordi · **Posted:** Sun Aug 07, 2016 12:02 am

WWdiesel, I have to disagree about the shroud. In order for a shroud to be effective at ducting the airflow and preventing suction from around the edges of the blades, it needs to be seated MUCH closer to the blades than the 3/8"-1/2" spacing that the factory shroud is. This is mostly due to the fan being mounted to the engine and the shroud to the radiator, they cannot move in concert with each other so since the engine will rock back and forth with normal performance, a closer fit would have the fan hitting the shroud.

As far as the amount of airflow, I tend to agree that the plastic fan will move the same or more air at the same speed b/c there is an at least equal amount of surface area of the blades.

Testing the clutch needs to be done with an oven though, it will be very difficult to get an accurate gauge of the clutch's temperature and performance while on the engine. You have to measure the front of the clutch, that is where the thermocoil is. If that coil doesn't expand / engage the clutch's brake at 170 or so, then the engine temps could easily be much hotter - don't forget it won't be receiving the actual engine temp, but a cooler mix of the airflow through the radiator and the radiator's temp. That is why a 170* clutch might match with an engine temp of 215 or more.

Mass-hole - Do you have an EGT gauge? With increased turbo boost and fueling, I would be curious about your cylinder temperatures and how it compares to stock cylinder temps.

WWDiesel · **Posted:** Sun Aug 07, 2016 11:13 am

I do believe the 11 blade fan does fill the shroud a little better than the metal fan.
As to the shroud: Safety First! protects fingers!!! :roll:

Without a shroud air flow is dispersed in all directions and is not controlled. With a shroud the air flow is controlled and directed through the radiator and out the back of the shroud over the engine thus not allowing hot air to recirculate back through the fan blades which would make the fan much less efficient. There is much available ASE information on the benefits of radiator shrouds!

I do agree that a tighter fit of fan vs shroud would be better but since the fan is mounted on the motor and the radiator is mounted to the frame and is stationary there has to be some clearance to allow engine movement without these parts contacting each other.
A good fan/shroud setup, provided the fan clutch is working properly, will produce a low pressure zone behind the radiator thus inducing better air flow through the radiator at all times and across all operating ranges....

Quote:

From Hayden Automotive: Thermal clutch operation, Severe Duty Thermal
engages at ~170 degrees F radiator air temperature (about 30 degrees lower than engine coolant temperature)
Turns the fan 80-90% of the shaft speed when engaged
Turns the fan 20-30% of the shaft speed when disengaged

geordi · **Posted:** Sun Aug 07, 2016 1:01 pm

I have not heard of a single CRD that has opted to use the fan shroud mod and discard the bottom half, having temperature problems. Several members (myself included at the moment) are operating with no engine fan at all, and while I cannot speak for the others, I am monitoring the engine temps on mine and they are not exceeding what the thermostat allows - 203 is the usual temp, even in the heat of South Florida. The electric fan is running because of course I have the AC on, so that probably provides more than enough cooling.

With the need for cooling the strongest when moving and towing, especially on grades, the ability for "uncontrolled" airflow even without a shroud is severely limited. Simply because of the forward motion, there will be a large amount of airflow all moving in the same direction. You are correct that the fan will create a low pressure zone directly behind the radiator though, which will forcibly suction more air through the radiator with or without the shroud - Newton's laws of motion in practice, as the airflow will want to continue in the same direction of motion rather than air behind / above / to the sides of the fan reversing direction to go back through the fan flow again.

I would like to see an overall comparison of fan airflow numbers for the plastic versus metal fan blades, but that is more theoretical than practical at this point. The practical results have been duplicated many times: Whatever your fan and shroud situation, if you are having heating issues while working the engine hard, the most likely solutions are the fan clutch and removing any water restrictions such as a failed thermostat.

I have seen several CRDs with heating issues (and not in the mountains) have those resolved by replacing the crown thermostat with either the factory unit or Jeff's - Apparently the failure mode of the crown is to reduce the outlet opening over time, getting weaker and weaker until failing closed. Not good. There was a brand of thermostat element on the TDI that would do this too, and anyone that replaced the thermostat usually saw their temperature issues gone almost immediately, CRD or TDI.

WWDiesel · **Posted:** Sun Aug 07, 2016 1:35 pm

My shroud is modified, two piece design now, separates in half but all of shroud is in place, upper and lower! No heating issues at all and hope I never have any! Not much towing and only light loads when I do and there aren't any mountains here in central Georgia but plenty of very high humidity heat. I went to the GM 11 blade fan and Hayden severe duty fan clutch simply trying to get a little better AC cooling in stop and go low speed town traffic and it seems to have helped AC cooling in the car quite a bit so far so I feel it is moving more air flow...
For now, I will keep my shroud and fan, to each his own! Although I am not opposed to an electric fan mounted on the back of the radiator if there is room for a decent one. I do believe electric fans have the ability to be more efficient than mechanical fans when sized correctly!

As to the thermostat, have no idea as to what is on it, came with it when vehicle was purchased used. Looks OEM to me, gauge reads just a tic left of center all the time when up to normal operating temperature, and it gets there fairly quick right now in this heat... If it ever fails, and I hope it does not, I will most likely replace it with an OEM unit unless I got some extra funds available to purchase the high dollar unit...

mass-hole · **Posted:** Mon Aug 08, 2016 11:22 am

WWDiesel wrote:

I respectfully disagree on removing the fan shroud! Removing it will make the mechanical fan a lot less efficient when it is in service at correct speed. It is not that big of a shroud to start with and does not cover much if any of the backside of the radiator.
If your fan clutch is bad, it will not increase the fan speed as it should when the temperature loading starts. With the engine hot, turn engine off and try to spin fan by hand, it should be very hard to turn. If it spins freely, clutch is bad!

As to the 11 blade fan; yes 11 blades will move more volume of air as opposed to a stock 5 blade fan given they are the same diameter IMHO.... :wink:

The GM 11 blade fan / Hayden HD Clutch I choose does set a little closer to the motor which puts the fan right in line with the end of the shroud which I think makes it a better choice than the Mopar 11 blade fan....

Have you tried the old trick when pulling the grade and it starts heating up to cut off the AC, cut the heater on high (windows down of course) and see if that helps any with the heating up?
Are you running the correct antifreeze? And lastly have you tried adding some Red Line Water Wetter to the coolant to see if that helps any?

What I meant was, remove the fan and shroud at the same time. Run it with no fan or shroud. I cant imagine the fan is providing any additional flow over what is being forced through the grill from the forward movement of the jeep when I am cruising along at 70mph and 2000 rpm. In fact, I suspect it may be a slight restiction if anything. Since I dont do any heavy towing at slow speeds then I cannot see the fan doing much for me anyways since I am never spinning the motor fast enough to get a substantial amount of flow.

Removing the shroud would allow the natural flow of air to be able to flow through the entire area of the radiator and not have to funnel down through the fan opening, which is partially blocked by the fan blades.

geordi wrote:

I have not heard of a single CRD that has opted to use the fan shroud mod and discard the bottom half, having temperature problems. Several members (myself included at the moment) are operating with no engine fan at all, and while I cannot speak for the others, I am monitoring the engine temps on mine and they are not exceeding what the thermostat allows - 203 is the usual temp, even in the heat of South Florida. The electric fan is running because of course I have the AC on, so that probably provides more than enough cooling.

With the need for cooling the strongest when moving and towing, especially on grades, the ability for "uncontrolled" airflow even without a shroud is severely limited. Simply because of the forward motion, there will be a large amount of airflow all moving in the same direction. You are correct that the fan will create a low pressure zone directly behind the radiator though, which will forcibly suction more air through the radiator with or without the shroud - Newton's laws of motion in practice, as the airflow will want to continue in the same direction of motion rather than air behind / above / to the sides of the fan reversing direction to go back through the fan flow again.

I would like to see an overall comparison of fan airflow numbers for the plastic versus metal fan blades, but that is more theoretical than practical at this point. The practical results have been duplicated many times: Whatever your fan and shroud situation, if you are having heating issues while working the engine hard, the most likely solutions are the fan clutch and removing any water restrictions such as a failed thermostat.

I have seen several CRDs with heating issues (and not in the mountains) have those resolved by replacing the crown thermostat with either the factory unit or Jeff's - Apparently the failure mode of the crown is to reduce the outlet opening over time, getting weaker and weaker until failing closed. Not good. There was a brand of thermostat element on the TDI that would do this too, and anyone that replaced the thermostat usually saw their temperature issues gone almost immediately, CRD or TDI.

Are you running no shroud at all, or just not lower half?

geordi · **Posted:** Mon Aug 08, 2016 12:03 pm

At the moment on this CRD, no shroud and no fan. The only times I feel any change in the air conditioner is when I stomp on it, and I suspect the computer cuts off the compressor to deliver all the power to the wheels. The temperature needle never moves.

Most of the CRD's I've worked on are running around without the bottom half of the shroud, and whatever fan they had at the time.

I have both the metal as well as the plastic fan to put on, so I can do some temperature experiments. I'm heading out for an errand in a few minutes, I will bring my IR temp gun and shoot the thermostat housing and a couple other places once I get there, to see some actual numbers of a hot engine in a hot and humid 85-90 environment with no fan.

mass-hole · **Posted:** Mon Aug 08, 2016 2:02 pm

Ok so I just pulled the fan and shroud. I trimmed the top of the shroud off so I could put it back on top of the radiator to make sure air doesn't blow through to gap in the top between the CAC and Rad.

I'll try this out and see how it works. I did also cut the shroud in half in case I do need to put it back in with the hayden clutch.The fan and clutch spent an hour or so in the oven with zero change in the resistance. It did have a little resistance to turning but I could do it by hand no problem.

flash7210 · **Posted:** Mon Aug 08, 2016 4:30 pm

I've been running without the engine driven fan for several years. On hot summer days, coolant temp do seem the be a bit higher without the fan shroud.
Driving at highway speeds is never a problem but at slow speeds there is not enough airflow.
Remember, the electric fan only comes on when the AC is on or when coolant temp gets above 210.

geordi · **Posted:** Mon Aug 08, 2016 5:47 pm

Here ya go - It wasn't as hot out today (dreary and rainy actually) but this was after about a 15 minute drive on the highway and several lights after getting off the highway.

As you can see, with a coolant block in place (EGR is completely deleted and that port is plugged) there is only a 2 degree difference between the far side of the head behind the alternator and the thermostat outlet.

undrgnd · **Joined:** Sat Mar 26, 2016 4:47 am **Posts:** 194

Soooooo much more room. Why can't we add the below two items?? Works for a lot of high power petrol cars why not a diesel (don't know much about diesels). My thoughts would be to install similar items to the ones below and controlled by http://www.haydenauto.com/Featured%20Pr ... ntent.aspx

Thoughts??

mass-hole · **Posted:** Tue Aug 09, 2016 11:04 am

undrgnd wrote:

Soooooo much more room. Why can't we add the below two items?? Works for a lot of high power petrol cars why not a diesel (don't know much about diesels). My thoughts would be to install similar items to the ones below and controlled by http://www.haydenauto.com/Featured%20Pr ... ntent.aspx

Thoughts??

There are some folks that have switched to electric fans. The issue is that supposedly our factory fans are capable of like 5000+ cubic feet/min of flow while the biggest electric fans are 3600 cu ft/min.

I was wondering the same thing though. My 2014 F150 Ecoboost uses two smaller electric fans and has no issues whatsoever. Its tuned and is probably making 430+hp and 500+ ft-lbs and weighs 6500 lbs and has no issues with cooling. I gotta think the jeep's issue is how they stack the CAC, A/C condenser, and Radiator in a row with little flow area.

mass-hole · **Posted:** Tue Aug 09, 2016 2:38 pm

After a few rides in 85-90 degrees, I would say that the cooling isn't any better or worse with the bad fan clutch and shroud removed. It still sits around 203F regardless of speed as long as it's partial load, only when climbing 7% grades at 100% load(21 psi, full fueling) in 5th does it spike.

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Hayden HD Clutch and HDS 203F Tstat

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