Testing viscous fan

[john.thompson068]

Testing viscous fan/engine runs too hot at idle.

My motor will run as hot at 230* if it is just sitting there idling. Often it will run at 210-220* when stuck in traffic. As soon as the car is moving it runs at 160-180*. I ran the following test on my fan. The fan is an 18" MP viscous fan. It is the same fan as seen in the picture below.

With the engine cold, I went to spin the fan and it spins freely with very little resistance. I warmed the car up all the way to 212*. Several times I stopped running the car and went to spin the fan. It still turns freely with very little resistance even when at 212*. The fan is spinning very fast at idle and is generating a lot of air movement across the entire engine. I increased RPMs to like 3 or 4 thousand from under the hood, and the fan really picked up speed. My very short hair was getting blown straight back so it was really moving some air. I then grabbed a piece of cardboard and folded it up and used it to try and stop the fan while the engine was running. The fan did not stop spinning and started to chew up the cardboard.

My fan was purchased new and is low mileage. Is there something wrong with my fan?

The rest of the cooling system consists of a 20x18 radiator, it is the biggest one that will fit in the car. I only have 2" to spare on either side of the tanks. The opening in the support is the same width as the cooling surface of the radiator which is 20" across. If you add in the width of the tanks, the radiator would be a 24". You can see it has an aluminum water pump, and a fan shroud kit. The thermostat is pretty low mileage, but I have no idea if it's a 160* or 180* because it was so long ago I replaced it. The rad stays full of coolant almost to the very top and has a 19-21lb Moroso cap. The motor is your typical pump gas 550 hp 440. There is a B&M trans cooler sitting in front of the radiator on the front side of the radiator support, but it is small and covers less than half of the radiator.

Looks like I may have to buy a small pusher fan for the front of the radiator on that one side. Eventually, when I install air conditioning, their is some kind of cooler thing for the air conditioning that goes in that same spot as the trans cooler. So later I will have to buy one of the long skinny trans coolers and mount it underneath the radiator to make room for my air conditioning condenser unit or whatever that things is.

 

[Sweet5ltr]

The known is that you are running at great temperatures while driving, and also that you are nearly over-heating while in traffic. You have plenty of air flow while driving at speed, you are NOT receiving ample amounts of airflow or CFM while idling. I am sure your transmission cooler, that is virtually blocking half your entire usable radiator core is another root cause. I would install a pusher fan and mount an inline transmission cooler. You need additional cooling, and I don't believe your mechanical fan setup is to blame (without going into if your fan clutch is operational). Once hot, the fan should be very hard to turn. If it is easy, I would suggest a new fan clutch. Our 550HP cooling combo is borderline cool (meaning, it just' fits the bill) even with the additional 1600CFM electric setup. We are running a summit racing electric fan, and it hasn't failed us "yet". It is wired in with the ignition, so it is constantly on. I do not believe the car would run cool without the electric pusher fan and our engine driven fan is straight mechanical. Remember, more horsepower requires more cooling!

 

[godfatherofchry]

you should not be able to spin that fan if you get ahold of the left side and give it a spin it should stop wen you move your finger off.put your cardboard in front of rad.and the fan or suction should hold it.I'm betting it wont.if it don't put a fan on it.or get another clutch for it..any thing over 200 deg.scares the hell out of me......Artie

 

[john.thompson068]

you should not be able to spin that fan if you get ahold of the left side and give it a spin it should stop wen you move your finger off.put your cardboard in front of rad.and the fan or suction should hold it.I'm betting it wont.if it don't put a fan on it.or get another clutch for it..any thing over 200 deg.scares the hell out of me......Artie

It does stop. It does have some resistance. When I grab the fan and give it a spin it stops right away. So this sounds like it is working fine. I was under the impression that when the motor heated up, when you went to spin the fan by hand, it would be impossible to spin because it would be locked and would only spin if the pulley moved. Apparently I misunderstood that.

As far as the over 200 business. Yeah it sucks, and can make you get nervous if you run into a really bad traffic jam. But it has been running hot like this for years and I have never had a problem. When you think about it, 230* degrees isn't really that hot. You can barely even cook food at that temperature so I can see why my engine has yet to have any problems with 210-230*. I am already planning a pusher fan project for next week or so. Money is non existent, or I would do a puller and pusher fan, alternator upgrade, and ditch that mechanical fan and shroud.

 

[john.thompson068]

I am sure your transmission cooler, that is virtually blocking half your entire usable radiator core is another root cause. I would install a pusher fan and mount an inline transmission cooler.

This I must disagree with. The trans cooler is open and allows air to go right through it even easier than the radiator. I believe it is supposed to be installed where it is. Plus there is a nice gap between it and the radiator. I am installing air conditioning as soon as I can get paid some decent money again. There is a giant thing just like that trans cooler that must be installed in that exact spot. It is a reproduction air conditioning setup identical to what was originally offered. So that space right there is not going to be able to be opened up. With a pusher and puller electric fan I should be running cool. I will have to run the same type of setup as you for a while with a small pusher fan on the passenger side of the radiator and the mechanical on the other. Later when money becomes available I will scrap the mechanical fan and shroud for a top of the line puller to run in conjunction with the pusher.

 

[ga66mopar]

I believe factory hemi cars used a secondary trans cooler in front of the rad. So I don't think that is the problem.

You're not using the 440 source aluminum water pump housing are you. I had one then I read a post on dodgecharger.com about a guy having the same overheating problem you are having. He took off the housing and noticed how small the water ports were compared to a original housing. He replaced the alum housing with the original cast iron housing and his overheating problem went alway. Before I even started my newly rebuilt 440 I pull off the alum water housing I bought from 440 source and he was right the water ports were about half the size of the original cast iron housing. I ordered a new alum housing from mancini and the ports on that one was the same size as the original cast iron piece. I have had my 440 idling in stop and go traffic in the heat of summer and I have never had a overheating problem. I have the original rad and regular mopar clutch fan. Your set up should be way better then mine. Hope this helps.

 

[Sweet5ltr]

This I must disagree with. The trans cooler is open and allows air to go right through it even easier than the radiator. I believe it is supposed to be installed where it is. Plus there is a nice gap between it and the radiator. I am installing air conditioning as soon as I can get paid some decent money again. There is a giant thing just like that trans cooler that must be installed in that exact spot. It is a reproduction air conditioning setup identical to what was originally offered. So that space right there is not going to be able to be opened up. With a pusher and puller electric fan I should be running cool. I will have to run the same type of setup as you for a while with a small pusher fan on the passenger side of the radiator and the mechanical on the other. Later when money becomes available I will scrap the mechanical fan and shroud for a top of the line puller to run in conjunction with the pusher.

Yes, it is "supposed" to allow ample air flow to pass through it yet anything that blocks the front of the radiator reduces available air flow through the core. It's not an issue if you place a pusher fan on your un-blocked portion, but I have seen some transmission coolers have a small individual pusher fan in front of them (if you have clearance). Many vehicles run a transmission cooler, but not many vehicles are making 550HP either so the debate of a factory car that is making 450HP to a highly modified engine making 550HP is not even remotely similar. Once again, I am not saying this is the MAIN ISSUE but it could create a problem when running a standard clutch fan setup. I run a large pusher fan (2000CFM) and a straight mechanical HD police fan. I don't believe its a prime issue, but if your current viscous fan cannot pull enough air flow through the core at idle; it needs every bit of help it could get! Install a pusher fan, and let us know how it goes. Hopefully it all works out for you, like everything else!

 

[john.thompson068]

Will do. I am on Summit right now scoping some out. If you don't mind, what is the part number or CFM of the fan you are using? Also, I may replace the thermostat sometime this week just so I know for a fact it is a 160* and it can be ruled out as a problem.

 

[Sweet5ltr]

I stand corrected, I am using a 2,010cfm electric fan. Here is the link;
http://www.summitracing.com/parts/SUM-G4904/

I believe it may be too large for your application with the transmission cooler. Check out my restoration thread, and you can see how large the fan is on front of the radiator.

 

[john.thompson068]

Check out this fan you guys! I can make that fit into the open space on my radiator. This is the best option I can come up with for a pusher fan. I can mount it the exact same way my trans cooler is mounted on those aluminum brackets and it will fit. Somehow, this fan pushes twice the cfm of other similar size fans, but is only a little more expensive. Let me know what you think of this fan.



http://www.summitracing.com/search/?keyword=Derale Cooling Products 16925&dds=1

 

[Sweet5ltr]

Check out this fan you guys! I can make that fit into the open space on my radiator. This is the best option I can come up with for a pusher fan. I can mount it the exact same way my trans cooler is mounted on those aluminum brackets and it will fit. Somehow, this fan pushes twice the cfm of other similar size fans, but is only a little more expensive. Let me know what you think of this fan.



http://www.summitracing.com/search/?keyword=Derale Cooling Products 16925&dds=1

Looks good, but check out that amp draw.. YIKES!
If you could go to a 14", Zirgo has some great options that have low amp draw (10amp) and flow very well at over 2,780cfm. They have a 10" also, that is 1150cfm with a 7amp draw. Allstar sells a 13" with only a 9amp draw, that produces 1530cfm for under $80. If you have a charging system capable of supporting that many amps, then I would go with your selection. If it's a factory style alternator, it probably isn't going to cut it!

 

[tpodwdog]

a 20x18 inch radiator on a 440 c.i. pushing 550 horses? and youre asking why you are having cooling probs? am i missing something here?

 

[70rr-brian]

a 20x18 inch radiator on a 440 c.i. pushing 550 horses? and youre asking why you are having cooling probs? am i missing something here?

I tend to agree with this...

I run a 555hp motor with a stock fan and no shroud with a Champion radiator (4 core) from the People Republic of Lead Paint and it never goes higher than 185 degrees. I can sit in traffic on 100 degree days or be blazing down the road pulling 4k rpms for miles at a time and she never gets off 185.

That same motor with a 22" factory rad would run at 210-220 all the time.

 

[Sweet5ltr]

a 20x18 inch radiator on a 440 c.i. pushing 550 horses? and youre asking why you are having cooling probs? am i missing something here?

His radiator is much higher performing than stock; with a dedicated shroud. It could be a variety of problems, but the cheapest route to a fix would be an electric fan. I believe he is measuring the usable portion of the radiator as well, because common sense would tell us that the radiator isn't 20x18 inches. If you can tell by his pictures, he is using all the available core area of his application through the grill. A Direct fit radiator is around 26-30" wide and 18-20" high with somewhere around 20-22x18 inches of core width. I am using a universal aluminum 26x19in. radiator with a 550HP 11:1 451. Link;
http://www.summitracing.com/parts/SUM-380425-3/?rtype=10

 

[john.thompson068]

Looks good, but check out that amp draw.. YIKES!
If you could go to a 14", Zirgo has some great options that have low amp draw (10amp) and flow very well at over 2,780cfm. They have a 10" also, that is 1150cfm with a 7amp draw. Allstar sells a 13" with only a 9amp draw, that produces 1530cfm for under $80. If you have a charging system capable of supporting that many amps, then I would go with your selection. If it's a factory style alternator, it probably isn't going to cut it!

Yeah, factory alternator. I hadn't gotten to the part where I am supposed to factor in the amp draw and the affect it will have on my alternator. I will have to start a whole thread on this topic. I could probably fit either the 10" or the 13" you mention so I will look for those.

 

[john.thompson068]

I tend to agree with this...

I run a 555hp motor with a stock fan and no shroud with a Champion radiator (4 core) from the People Republic of Lead Paint and it never goes higher than 185 degrees. I can sit in traffic on 100 degree days or be blazing down the road pulling 4k rpms for miles at a time and she never gets off 185.

That same motor with a 22" factory rad would run at 210-220 all the time.

Sweet5ltr is right. Sorry you guys. If you measure the whole radiator it is a 24x18 4 core aluminum radiator. I could not fit a larger one in the car as there is only 2" of space on either side of the radiator before it would hit the inner fender well.

Also, I just purchased a 160* thermostat for 6 bucks to make sure that is what I have. That is the one I should have in there already, but will find out when I replace it regardless.

 

[Sweet5ltr]

Cooling issues aren't always an easy one to diagnose, and no one issue is like another. With a 160* Thermostat and an electric fan that draws less than 10-12amps that flows 1500CFM should be plenty enough. Just because one engine runs cooler with "x" amount of power, does not mean another engine of equal power will run similar temperatures. I know how over-heating feels, because we had similar issues with only 450HP. Now, we have 550+HP and run the same temperatures. Cooling is an area where you should overbuild, rather than under-budget and just try and get by. If you're running a 65amp alternator like myself, then I would really try and only go toward the lower amp offerings. These aren't modern electrical systems, designed for massive electronic use and performance. Just my thoughts.

 

[subboz]

It appears there might be two things I see but might just be optical.
Where is the fan sitting in relation to the shroud opening. Looks like the blades are really tucked in there. They should be in the circle as to not allow air to circle behind them. Remember path of least resistance. IF air can just circle around from behind to the front instead of through the rad it will.

As for thermostat. Goal is to act like a switch one and off to allow coolant to cool sufficient in the radiator. 160 is great if you got a monster cooling system or trying to squeeze some HP out of a FI motor. Once temp reaches 160 it just stays open and fluid can not cool fast enough at idle or low rpms when airflow is less. IF it was the 180 or factory temp it would open and once liquid cools below it will open again and start cycle again.

And how is timing. IF it retarded just a bit that can make it run hotter as well. 10 degrees is a big difference in your upper end.

just my two cents

 

[john.thompson068]

I either bought the 50A or the 60A cause that is what the parts store just told me they had available for my car. There is no way for me tell which one I have unless there is a special test I can do with a voltmeter. What is up with that 11.75" 2210cfm fan drawing 23.4 amps? I am comparing it to a 16" 3300 cfm fan that draws only 18 amps. That 23.4 amp fan must need all that power to push that much cfm with such a small fan blade right? I don't know if I would bother with that 23.4 amp fan even with a 90 amp alternator. I am beginning to doubt that its benefits are worth the amount of power it takes. Especially if you have another fan acting as a puller fan. I am seriously considering that fan you recommended, but I am also seriously considering just doing an alternator upgrade too. I have concluded my research on alternator upgrades and am making another thread over in the electrical section. Please take a look at that you guys. If I had a 3300 cfm fan with 18 amp draw, and a 1500 cfm fan with a 10 amp draw, that would be almost 5000 cfm of air flow. That would have to be enough to cool any motor, and only drawing a total of 28 amps, which is barely more than that single fan alone. That 23.4 amp fan is crazy.

 

[Sweet5ltr]

It appears there might be two things I see but might just be optical.
Where is the fan sitting in relation to the shroud opening. Looks like the blades are really tucked in there. They should be in the circle as to not allow air to circle behind them. Remember path of least resistance. IF air can just circle around from behind to the front instead of through the rad it will.

As for thermostat. Goal is to act like a switch one and off to allow coolant to cool sufficient in the radiator. 160 is great if you got a monster cooling system or trying to squeeze some HP out of a FI motor. Once temp reaches 160 it just stays open and fluid can not cool fast enough at idle or low rpms when airflow is less. IF it was the 180 or factory temp it would open and once liquid cools below it will open again and start cycle again.

And how is timing. IF it retarded just a bit that can make it run hotter as well. 10 degrees is a big difference in your upper end.

just my two cents

Good insight, I had a 185* thermostat and it was removed. It worked great if your entire cooling system was up to par. Even the Direct Connection engine manual states to run the coolest thermostat possible to create the greatest performance and drive-ability from your engine. I had no issues with the warmer thermostat, but the cooler the engine can run; the greater the performance. It's a noticeable difference while driving. We all want that, right? Better low speed drive-ability and increased power for less than $10.. :headbang: