Cooling fans

[oka065]

Has anyone out there ever fitted a Horton stile fan clutch to a 6.5? My fan hub sits to low on the radiator for it to sense hot air.

Regards Rod

[DmaxMaverick]

If your fan is able to draw air from the radiator, the clutch is getting plenty of "sample air" to work the clutch. The clutch is really very sensitive to temp changes. It is more the function of the thermostat(s) to raise the radiator air temp, causing the clutch to engage the fan. If your clutch is good, I'd look at the thermostat(s) for any concerns you have about fan engagement.

What problem prompted you to think the clutch isn't working properly?

While a Horton style clutch would allow you to set engagement/disengagement points absolute, it also eliminates the automatic function of fan engagement. IMO, this is counterproductive. A healthy cooling system will synchronize the fan engagement with thermostat function. Having the fan engaged with closed thermostats wastes energy. On the flipside of that argument, having more air flowing through the other coolers (oil, tranny, A/C condensor) could be beneficial. An electric auxilary fan may be better suited for this, if you need it.

[oka065]

G,day, this is how it goes. I have fitted a new 6.5 center turbo to a vehicle called an OKA ( australian male ) this is a localy Westerm Australian built truck, weighs about 4.5 tons, was fitted with a 4 lt Perkins. We fitted the 6.5 + 4L80E + Nissan Patrol transfer case goes great heaps of power, but if we travel much over 60 mph or go up a hill the temp gauge reads over 210 deg f at around 60 & below on a 90 deg f day it will run at around 180 deg f.

I have 160 deg f t/stats fitted, maybe here is the problem. The radiator is cooling ok I have thermo-couples measuring the temp differance is around 70 deg f hence the lower part of the radiator is cool. I have fitted one of Bill Heaths severe duty fan & hud but as I say it isnt engaging. I do have one of Bills balance flow cooling systems that I still have to fit ( doing things in steps to see if I can fit problem ).

Love the motor & tranny combo, running a manual injector pump as there isnt a stand alone computer to run it, still good though I cranked the fuel up a bit goes great ( wife likes it more now that it will pass what we call a road train ( truck & 2-3-4 trailors.)

Maybe I will fit the balance flow & warmer t/stats, then see what happens. It is summer time here now so it is a good time for testing & fixing.

Thanks for you comments so far look foward to more.

[rjwest]

The fan needs to to have a shroud to direct the air around the Fan, if radiator has no aft shroud cooling is reduced especially in hot weather..

[Kennedy]

The fan clutch that you installed is the OEM stock replacement which seldom if ever works properly due to excessively high engagement. Is yourfan shrouded like the GM truck is, and how far from the radiator is the thermostatic coil?

[oka065]

Yes we do have a shroud around the fan & the sensing coil on the fan is about 2" from the radiator. When we first fitted the motor we were only using the OEM radiator & the fan & hub that came with the motor. Then the fan would cycle in & out, but the motor would still run hot going up-hill. Then we talked to a radiator expert & he fitted a 3" longer core. The results from this is above!

[DA BIG ONE]

Originally posted by oka065:
G,day, this is how it goes. I have fitted a new 6.5 center turbo to a vehicle called an OKA ( australian male ) this is a localy Westerm Australian built truck, weighs about 4.5 tons, was fitted with a 4 lt Perkins. This conversion you did sounds great, perhaps you can give us yanks a view of some pictures.

[DmaxMaverick]

Yes. Pictures would probably help your diagnosis as well.

If all else is well, and you still have heat issues, you may have an issue with engine compartment pressure. When up to speed, the engine compartment needs to be at less than positive pressure, or minimal air will pass through the radiator, and less passes across the engine and components. This causes heat soak, with no way to get rid of the heat. An example of this is some cases where an aftermarket "air induction" hood of poor design is used. In order for air to get in, it first has to get out.

[oka065]

Thank all, I will try to work out how to upload some photos so you can see my AUSSIE truck.