High coolant temps

[Pmaloney]

Well as I suspected my coolant temperatures are higher than I would like to see. Sunday I hooked up to my 30' gooseneck and headed up a hill and doing 70 mph up the hill I was at 230 degrees hill was only 1-2 miles so I dont know if it would stay at that temp or not but either way that is too hot for me. Soooo my question is I would like to either had a heater core in front of the intercooler or another radiator that I have laying around (90 Jeep Cherokee, long and short) in the front of the bed of the truck. I was going to use the factory heater core return line to run to either of my options since I dont have a service manual to see if there are any ports I could use. I know I could pull from the head but am not sure where to return the coolant (Need a service manual for flow charts!!) Anyhow I am leaving thursday or friday for the mountains with the mentioned trailer so time is of the essence. Any input would be great, Thanks!!! BTW I am running two electric fans 12" 4000 CFM and I do believe that I just need more cooling capacity due to the fact that after the hill it went down to 190 fairly quickly.

 

[bmoeller]

What temp is your t-stat? Is it working properly? I have a 180* stat in mine.



I am curious as too what the CFM is on a factory Cummins fan that is used on the Ram. Could be wrong, but I would think those two fans might be enough.

 

[Pmaloney]

I have a brand new Cummins 180 thermostat, and I to would also think the electric fans would be enough. I just believe that the smaller radiator I had to use (31x19. 2. 25 aluminum with 2 1-1. 25" cores) is just a little to small for towing, mabee in a lower elevation flat state it would be fine but not here.

 

[dcamilleri]

I don't think the electric fans can pull enough air. I just replaced my 19 inch stainless flex fan with a 22 inch 4600 series class 5 flexalite truck fan. What a difference! I too was hitting 230 plus pulling the high mountain passes and now seems to be at least 20 degrees cooler under all conditions. Noise is a little louder but it cools. I am running a dodge cummins radiator from a 97 in my set up since I was told that the stock chevy radiators won't hold up to the flow of the cummins. I also notice that if I try and pull a grade with egts over 1100 degrees that water temp starts to creep up.

 

[michigandon]

Which Flex-a-lite fan has the proper bolt pattern to mount to the Cummins pulley?

 

[JBlock]

I see well in 220

I see 220 towing before the Factory cummins fan comes on maybe evern 230.



Then it howls.

 

[dcamilleri]

I had a custom adapter machined that adapts the left hand threads of the fan pulley to a standard 4 bolt fan pattern. The heavy duty flexalite fans are available in every bolt pattern imaginable or even custom or blank.

 

[RustyJC]

I tried the dual Flex-A-Lite (Model 350??) fan setup on my 1996 V-10/47RE Dodge Ram 3500. It wouldn't cool the engine in towing applications. The fans drew (as I recall) 50 amps when both were engaged. 50 amps x 12 volts = 600 watts = 0. 8 BHP. Even if the electric fan airfoils were twice as efficient as the engine driven fan (and they're not), 0. 8 BHP just couldn't move enough air to cool the V-10 when dragging our previous 13,500 lb 36' 5th wheel through the Texas Hill Country.



I went back to the engine-mounted fan with a 205 degF fan clutch (228 degF was stock with the V-10), and my cooling problems disappeared.



It cost me $500+ to learn this lesson. You're welcome to take it for what it's worth.



Rusty

 

[Pmaloney]

I'll also second the lack of cooling while towing with electrics. I installed a 19" flex fan and it has helped (not solved yet) I still need to do a shroud that should help a bunch, I may also try a different fan possibly one that will move more air, anyone have any ideas/links?

 

[RustyJC]

The problem with an engine driven flex fan (generally speaking) is that they're made for high performance, not towing, applications. For a high performance fan, it's fine if the fan is at its maximum airflow position at or near idle - this will keep the engine cool while sitting at stoplights and general around-town cruising. This fan is designed to "flatten out" at high RPM to minimize engine BHP losses - of course, it moves little or no air and can actually block velocity air flow through the radiator because of the flattened blade profiles. For drag racing, that's fine - the engine is at max output for only 10-15 seconds - not long enough to heat up.



For towing, however, high RPM work (i. e. , dragging a 5ver up an 8% grade) is exactly where we need maximum cooling. That's why, for towing applications, I prefer a factory-type non-flexing fan with a thermally-activated viscous clutch.



JM2CW...



Rusty

 

[Pmaloney]

That is what I would like to do but I dont think I have the space for a clutch, I may have to go with a solid mounted "stock style" non flex fan. Mabee the flex a lite nylon fan?? Ideas?

 

[michigandon]

I too would like some alternatives in case this Zirgo electric fan doesn't work out. I MIGHT be able to shoehorn a fan in between the pulley and the radiator. However I know there's no way in H E double hockey sticks that a clutch will fit in there. :{



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And there ain't no movin' nothin' ahead either! As it stands now, the Ford FlowerJoke intercooler is going to be about 1/4" behind the grille when all is said and done:

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The gentleman whos been mentoring me on this project and also repowered a coach exactly like this one keeps bragging to me about how he drove his for over 25,000 miles with NO fan. I'll keep you guys posted on the end results once I get it roadworthy.



Don

 

[dcamilleri]

Pmaloney,

Go to flexalites' web site and click on heavy duty otr fans. Then click on the 4600 series fan. This is a nylon fan with an aluminum center. If you are running a flex fan now you can run one of these. I chose the 22 inch version. It pulls massive amounts of air. I am very happy with the improved cooling that this fan has made. Oo.