fan clutch

[North Maine]

1. what temp should the fan engage at? mine used to stay silent until well over 200*, but last night it was engaging around 190* and staying on longer than it needed to, pretty annoying around in town.

2. should the fan spin freely when cold? mine will spin maybe 25* before stopping, there is a lot of resistance.

3. with the Duramax upgrade, I'm looking at the Big 3 of the 6.5s, (SS, Heath, KD) and there are differences between them all. The heath system uses the stock calibration fan clutch and the dura fan, but is 300 bones. The SS system uses a lower temp calibration and the dura fan, for 189, and the KD system wants to reuse the steel fan, which by all acounts is a bad idea... so this is pretty much to those with the dura fan upgrade... who did you buy from, why, and what differences did you notice?

 

[beaglehauler]

have you cleaned it ,they get lots of crud in them

 

[JiFaire]

1. what temp should the fan engage at? mine used to stay silent until well over 200*, but last night it was engaging around 190* and staying on longer than it needed to, pretty annoying around in town.

Fan engages on air temp, not water temp... important. Why? The air going through your rad picks up heat, then hits the thermocoil at the face of the clutch, causing it to engage. Dirty rad, poor airflow, etc can cause the fan clutch to engage at the wrong time (or not engage at all). If you don't get airflow, your fan also won't DISengage, because it can't cool off. Most often seen when vehicle is not moving, or pulling really heavy in slow traffic.

2. should the fan spin freely when cold? mine will spin maybe 25* before stopping, there is a lot of resistance.

Fan is on a viscous clutch, so no, it should NOT spin freely. The fan clutch never completely "disengages".

3. with the Duramax upgrade, I'm looking at the Big 3 of the 6.5s, (SS, Heath, KD) and there are differences between them all. The heath system uses the stock calibration fan clutch and the dura fan, but is 300 bones.

You better phone Bill Heath and talk about that... mine is a Heath, and it kicks in at a lower-than-stock temp. It is also a higher torque-transfer clutch, meaning that when engaged, the fan spins at closer-to-engine-rpm than the stock version. More info on clutches found at http://www.haydenauto.com/ or you can see a write-up at http://www.oliverdiesel.com/products/haydenfanclutch.htm

The SS system uses a lower temp calibration and the dura fan, for 189, and

Also a little fishy... the SS sells the stock clutch, not a special-calibration one.. You can get the same one from your dealer.

the KD system wants to reuse the steel fan, which by all acounts is a bad idea...

Kennedy uses a special-calibration clutch which kicks in 15*lower temp, but also tends to stay engaged too much when normal driving. Turbine Doc has had the Kennedy system and reports that he took it off because it was engaged too often, robbing fuel mileage and power (plus being noisy!) in favour of the Heath clutch and fan.

Kennedy recommends that users also get his special 9-blade steel fan, which does move lots of air. Don't know where you got the notion that this was a bad idea... you can also go to GM and buy a 2000 6.5 9-blade steel fan. They move as much air as the 9-blade composite duramax fan, which is more than your stock 6-blade steel fan.

so this is pretty much to those with the dura fan upgrade... who did you buy from, why, and what differences did you notice?

Mine has a Heath SD clutch and I kept my stock 6-blade steel fan. I pull reasonably heavy (9800 lb), in big mountains, with hot ambients (ie: through western Washington, Oregon and in Alberta/BC. No problems since upgrading my fan clutch, thermostat (Genuine ACDelco only!), cleaning my rad (properly!!), and installing a TCC lock. Before doing that, I overheated just THINKING about pulling the trailer!!

 

[North Maine]

how do you "properly" clean out a radiator?

 

[North Maine]

Also a little fishy... the SS sells the stock clutch, not a special-calibration one.. You can get the same one from your dealer.

I know, but unless he is outright lying in his product description, it is not the same as stock. To be honest, I would prefer a stock clutch with a d-max fan from the reading I've been doing. I dont tow, I'm just annoyed with the around town ROAR of the fan.

 

[Turbine Doc]

Had factory then after reading horror stories & pending doom to maybe overheat, I swapped to KD with steel, it kicked in earlier, stayed on longer, took 25 Hp to drive it per snap on scanner, (just a calculated # so may not be actual), swapped to Heath clutch/plastic fan only required 18 Hp to drive, seems to kick in earlier than stock, later than KD, engine still stays cool, even on very hard pulls on hot days.

But I have lots of other bells & whistles on mine, I'm very satisfied with Heath stuff on mine, before I found Heath I was all KD stuff on my truck, the 98 burb is 100% Heath upgrades, when I bought it 130K, it had cooling issues, would heat up in stop/go traffic 220F, cleaned rad & A/C core, replaced water pump to spin on hub with Heath clutch (old clutch was still working but was 4 bolt vs spin on new pump had) & plastic fan & have yet to see over 198F, the burb is mostly stock Exh-reflash-remote FSD, FS2500 are only mods on it.

Which is better ??? KD & SSD flip a coin, slight edge on KD over SSD, as SSD on some product claims have not lived up to their advertising, they make good most times but working through email only to resolve issues is a PITA.

Trash talk at both of those vendors is a big negative for me, your products can be very good quality as most of their stuff is but customer relation during & after the sale is important, and any vendor that starts out with "you don't want that junk" is not way to begin a conversation with me, I'm fine with an explanation of differences, but trash talk at onset is a huge negative IMO. Of course A1 Customs/DMAXBIZHOSTING found through google search or other search isn't even worth mentioning other than to issue the warning STAY VERY FAR AWAY from him.

 

[Turbine Doc]

I know, but unless he is outright lying in his product description, it is not the same as stock. To be honest, I would prefer a stock clutch with a d-max fan from the reading I've been doing. I dont tow, I'm just annoyed with the around town ROAR of the fan.

You rode in mine how was the "roar" there mostly it don't kick in until you are at highway speed

 

[North Maine]

i liked your set-up TD, but for 300 bucks I could go get a brand new dmax fan and brand new fan clutch, and make my own set-up, remember you tow heavy and live in MS, while I rarely tow and live in nice cool ME. If I wasnt in school, heath would be my instant choice, but given what he wants for the upgrade, I'm tempted by staying stock clutch, d-max fan

how much of an diff. did the rad. cleaning do for your burb?

 

[Turbine Doc]

Fan is on a viscous clutch, so no, it should NOT spin freely. The fan clutch never completely "disengages". unless bad, have come across a feww that almost never stopped spinning, as Jim says should have some spin resistance

Also a little fishy... the SS sells the stock clutch, not a special-calibration one.. You can get the same one from your dealer.



Kennedy uses a special-calibration clutch which kicks in 15*lower temp, but also tends to stay engaged too much when normal driving. Turbine Doc has had the Kennedy system and reports that he took it off because it was engaged too often, robbing fuel mileage and power (plus being noisy!) in favour of the Heath clutch and fan.

Kennedy recommends that users also get his special 9-blade steel fan, which does move lots of air. Don't know where you got the notion that this was a bad idea... you can also go to GM and buy a 2000 6.5 9-blade steel fan. They move as much air as the 9-blade composite duramax fan, which is more than your stock 6-blade steel fan.

Alex it's odd you don't have 9 blade steel already, both of my 98s had steel fans, I thought that was part of the 97+ year cooling upgrade



Mine has a Heath SD clutch and I kept my stock 6-blade steel fan. I pull reasonably heavy (9800 lb), in big mountains, with hot ambients (ie: through western Washington, Oregon and in Alberta/BC. No problems since upgrading my fan clutch, thermostat (Genuine ACDelco only!), cleaning my rad (properly!!), and installing a TCC lock. Before doing that, I overheated just THINKING about pulling the trailer!!

added comment

 

[North Maine]

I think mine DOES have a 9 blade, and to be honest it cools just fine. I *think* my fan clutch may not be in peak condition, and if it is going to engage I have heard that the d-max fan is not only more effective but also quieter. Thats the reason I'm looking into this.

all of this stems from my original radiator leaking back in april, which I just replaced with a used one from a 1995. Even without the tranny fluid running through it the engine temp is hotter than it ever has been, staying around 192 whereas before it was a LONG time for it to reach 185. I think there is more at play than the radiator, but i dont think this replacment is working as well as my original was.

 

[Turbine Doc]

i liked your set-up TD, but for 300 bucks I could go get a brand new dmax fan and brand new fan clutch, and make my own set-up, remember you tow heavy and live in MS, while I rarely tow and live in nice cool ME. If I wasnt in school, heath would be my instant choice, but given what he wants for the upgrade, I'm tempted by staying stock clutch, d-max fan

how much of an diff. did the rad. cleaning do for your burb?

I did all at same time, so can't say how much a difference it made, but your foundation to any cooling is clean rad, takes about 3 hours to do it properly go to ac&r shop get some foamy coil cleaner wash rinse repeat until you get no junk out of the core, same for A/C core as well, maybe get a "fin comb" straighten the fins, use high volume not high pressure water as you'll damage fins with high pressure.

Towing or not Heath is way to go IMO, one of those mods you do because it is cheap insurance, you say you don't tow, but you may, or what if you have a mechanical issue and your engine is running hotter than normal you will want extra cooling then, what kind of issue, oh maybe a WG solenoid, vac pump, or blown turbo hose, had all 3 of those happen, maybe you have tranny issue, myriad of "things to go wrong".

Save the coins upgrade to a better than OEM clutch. IMO before adding performance mods, add engine survivability mods, so your engine can handle the performance upgrades, that is way I've built/overbuilt mine, anticipating what I intend to make the truck do as well as perpare for the unplanned events that might happen.

 

[Brooklyn Tow]

Search "Fan Clutch", here and the old site, plenty of info.

Louis

 

[JiFaire]

how do you "properly" clean out a radiator?

hey Alex.. sorry I wasn't around today to answer that question. Look here.

If I was you, the first thing I would do is a rad clean as per the above link. Step #2 would be to change the fan clutch only. If you have a 9-blade steel fan, you won't get quieter by putting on a composite fan. Won't really move more air, either.

I'll bet the cleaning does the trick.

Jim

PS - Turbine Doc suggests using foaming AC Coil cleanser to soak and clean with, and he's usualy right about the technical stuff. I used 'scrubbing bubbles' foaming bathroom cleaner because it's what I had, and it seemed to work good. I used Formula 409 on a buddy's rig and it worked OK, too.

 

[North Maine]

thanks for the help Jim and Tim