Fan/Condenser/Trans Cooler Spacing

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carfreak6970

carfreak6970

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So I have a '90 W150 that I am trying to put a clutch fan on. Currently it has a flex fan that was not cooling it well at all in traffic but was cooling it fine at high way speeds. Being in Pittsburgh I need this thing to also stay cool in traffic.

I got the Hayden 2797 severe duty clutch and I mocked up the spacing below:

SSWDWSHBIZH36021213230.jpg


So currently the fan blades are about 3.25" from the back side of the radiator. Is this to far? It does have the factory shroud and what I have been reading is that it is more important that the fan be inside the shroud than how close the fan is to the radiator. Am I on the right track with this?

If I have to space the fan closer to the radiator, there would be no issue with modifying the clutch's flange that mounts to the water pump to accept longer bolts? I dont foresee an issue with this since the clutch is centered via the center post and not the actual bolts, correct?

The other issue I see with this is that the condenser and trans cooler seem pretty far away from the radiator (as compared to the 2001 Durango I had)(condenser is 1.5 inches from radiator, and the trans cooler is 2.625" from condenser, no shroud to tunnel air flow through them). Would it be a good idea to try and modify the mounts so that they are closer to the front of the radiator? I feel that if they were closer the condenser and trans cooler would cool more efficiently, correct?

I talked to my dad about this last night and the trans cooler was an aftermarket piece that the previous owner installed. The A/C cools down eventually and to my knowledge we never had transmission issues in the 208000 (minus the 52000 put on by the previous owner) put on it.

thank you for your help.
 
My personal preference is to put the trans cooler in front of the radiator. The air in front of the radiator is 100 degrees cooler which helps keep trans temps down. The air behind the radiator is much much hotter. Treblig
 
carfreak6970 said:
So currently the fan blades are about 3.25" from the back side of the radiator. Is this to far? It does have the factory shroud and what I have been reading is that it is more important that the fan be inside the shroud than how close the fan is to the radiator. Am I on the right track with this?
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You cannot have the fan "too far back" as long as it is into the shroud. You COULD however likely get it "too close"..........the fan might be so close to the core that turbulence reduces blade efficiency, and of course you run the danger of tapping the rad with the fan If you look at some of the horrid stuff "in the eighties" some of the fans were FEET from the radiator LOL



carfreak6970 said:
The other issue I see with this is that the condenser and trans cooler seem pretty far away from the radiator (as compared to the 2001 Durango I had)(condenser is 1.5 inches from radiator, and the trans cooler is 2.625" from condenser, no shroud to tunnel air flow through them). Would it be a good idea to try and modify the mounts so that they are closer to the front of the radiator? I feel that if they were closer the condenser and trans cooler would cool more efficiently, correct?
Click to expand...

I don't think I'd worry about the trans cooler, but I would certainly try and get good airlow through the condenser, so maybe get it closer if you can or at least make some "wings" on the side of the condenser to reduce air gap at the sides.
 
My bad!! I didn't notice that the trans cooler was already in front of the radiator. But yes, the condenser should be as close as possible to the radiator to help airflow (the closer the better)!!

treblig
 
I appreciate the feed back. On a quick forum search I have had some conflicting opinions on the condenser to radiator spacing. I was thinking of making "wings" or a shroud around the back side of the condenser to reduce the air gap. Just trying to get this thing to stay cooler in the traffic/hills out here
 
If everything is working fine except the radiator I think the "wing" idea would only direct more heat into the radiator but would get more flow to the condenser.
 
I'm pretty much right on track with 67Dart273 (Del)
If it cools fine at speed then that tells us the cooling system is capable, but just not enough air flow.
The clutch fan with the shroud should solve that.

I wouldn't even worry about the condenser spacing, because once that clutch fan and shroud are on there it'll be pulling through the entire radiator surface and all that air will be coming across the condenser and trans cooler anyway.
 
awesome okay. I just got the bolts to mount the clutch up to the water pump and hope to get this together for a road trip in mid September. going to be hauling back an engine, trans, engine stand, and engine lift across the state.
 
long ago memory from a long ago mag article with some good testing, but with the fan about 1/2 way into / out of the shroud, like the "some of those other people" pic above creates the most flow. too far in, the air bounces around in the shroud. too far out you loose suction
 
Treblig said:
My bad!! I didn't notice that the trans cooler was already in front of the radiator. But yes, the condenser should be as close as possible to the radiator to help airflow (the closer the better)!!

treblig
Click to expand...

I was wondering about ur post on the location, glad u caught it.
Disagree w/ the trans cooler being up tight against the rad tho. Most were put there for convenience or clearance issues.
 
famous bob said:
I was wondering about ur post on the location, glad u caught it.
Disagree w/ the trans cooler being up tight against the rad tho. Most were put there for convenience or clearance issues.
Click to expand...
Yes, the trans cooler can be almost anywhere except behind the radiator, frame rail, etc. Treblig
 
Awesome, Okay.

So I am gathering that the Trans cooler is fine where it sits, the clutch fan is good where it is (I mocked everything up last night and the fan blades will be about 50% in the shroud), and I should at least put some wings on the condenser or move it closer to the radiator.

Got it.
 
TrailBeast said:
I'm pretty much right on track with 67Dart273 (Del)
If it cools fine at speed then that tells us the cooling system is capable, but just not enough air flow.
The clutch fan with the shroud should solve that.

I wouldn't even worry about the condenser spacing, because once that clutch fan and shroud are on there it'll be pulling through the entire radiator surface and all that air will be coming across the condenser and trans cooler anyway.
Click to expand...

I just went thru every "known to man" fan combination on my 505'' barracuda. The clutch fan "short or long wouldn`t work for me , went back to single belt driven. Granted I don`t have room for taurus fans or a long clutch fan , but it seemed that the "short" clutch was big enough to block enough air to not work. I have the biggest crossflow rad I can get between the rails, out on the hi way it would cool down w/ a belt driven fan, but not so w/ a clutch type.
I do have new 2747 jaguar clutch for sale that is 2 5/8" tall, along w/ 3 elec fans, and a few mech. fans too.
My set engine up is on the edge tho . jfyi
 
famous bob said:
I just went thru every "known to man" fan combination on my 505'' barracuda. The clutch fan "short or long wouldn`t work for me , went back to single belt driven. Granted I don`t have room for taurus fans or a long clutch fan , but it seemed that the "short" clutch was big enough to block enough air to not work. I have the biggest crossflow rad I can get between the rails, out on the hi way it would cool down w/ a belt driven fan, but not so w/ a clutch type.
I do have new 2747 jaguar clutch for sale that is 2 5/8" tall, along w/ 3 elec fans, and a few mech. fans too.
My set engine up is on the edge tho . jfyi
Click to expand...

Understood.
The first thing that jumps out at me is "505" vs whatever he has in his truck.
 
carfreak6970 said:
The truck is the 360 with the stock TBI
Click to expand...

Gottcha.
I was making a point about bigger cubic inches needing more cooling capacity.
I wouldn't sweat the spacing one bit, because it really is going to make almost zero difference if any.
 
TrailBeast said:
I wouldn't sweat the spacing one bit, because it really is going to make almost zero difference if any.
Click to expand...

So your saying that the condenser is fine where it is and adding "wings" really wouldnt help with the condenser efficiency ( A/C cooling)? From what I have read on other forums they said the distance/wings would help with a/c cooling at low vehicle speed. Or is the improvement to the cooling so small that its not worth the effort?
 
So an update on this issue:

I was able to install the clutch fan (and hopefully fix that passenger window motor for good this time...) and got everything buttoned up this past weekend. I took it for a shake down to see how it would run since I plan on hulling a heavy load over some PA mountains this month. With yesterday being hot and humid I figured that would be great to try it out. I went to pick up paint at Home Depot and took the truck. It is about 10 miles away with the speed limit ranging from 45-25. There was some traffic lights but I would say about 60 percent back roads and 40% suburbia/mall roads.

I saw that the temp gauge was fluctuating between the normal position and half way into the safe range with the A/C on (which needs charged. Again. I am going to try and find a leak detector to see if I can find the problem area). Normally the truck did not do this, it always held a temp unless stopped. Once stopped it would creep up but would go back down once you got moving. Well I noticed the the gauge was half way into the safe range during one of the fluctuations, but instead of going down it continued to climb. well it climbed to outside of the safe range (I did not have a thermometer to verify the actual temp, and I never saw it get that high before). I understand it was hot, but not hot enough to have the gauge climb like that. Once I got it parked I tried increasing the revs, and that did not do anything.

It took awhile and a couple stops at a few stores on the way back, but I was able to get the truck back into the garage.

This is what I can think of:
When I felt the top radiator hose it was hot but I was able to squeeze it. It did not feel like there was a high rate of flow within the hose. So I am thinking that the thermostat was not opening fully, if at all. The fan was not roaring at all, but if hot coolant wasnt getting from the engine to the radiator the fan wouldnt have the hot temp of the fluid to tell it to engage more. So I got a new thermostat and installed it last night. I will put coolant back in and take it for another ride this week. The last time I had the truck out was to a concert and it got to the top of the safe zone sitting in traffic waiting to park. So it could be that the thermostat started to fail back then as well. The thermostat was last changed in 2001 at 122000 miles. It currently has 209000 miles.


Does my line of thinking seem on track? My old man thinks it has to be the clutch fan failing and I should put the flex fan back on since that didnt have the problem (Since the only new variable I added into the equation was this clutch fan). But I tend to disagree.

Thoughts?
 
For the sake of clarity, here is a picture of the gauge:

truck gauge.jpg

The temperature gauge is in the bottom left pod. There are 6 "vertical" lines within this gauge. I will refer to the two middle ones (the two lines the orange indicator needle is between in the photo) as the left one (for the one to the left of the orange indicator needle) and the right one (for the one to the right of the orange indicator needle). Between the left and right lines I am calling the safe zone.




I was able to fill the system up with coolant last night after I installed the new 195 degree thermostat and took the truck to work. It is about 8 miles with speeds going from 25-45 with the possibility of stop and go traffic. Not to sure about the temp this morning, Id say in the 70's with high humidity.

When I first started out the gauge was fluctuating around the left line. Which is okay. After awhile it seemed to hold steady around the left line. I am okay with this. I took this as the system "breaking in" the new thermostat. So I hit the first traffic light behind a couple cars. The temperature needle increased to just below the right line. Higher than I would like but still within the safety zone. Once I finally got through the light it was Pittsburgh hilly roads traveling about 30-45 mph. The gauge still held within the safety zone but about 2/3's of the way to the right line. After about 3 miles the gauge was reading about a quarter away from the left line. I then hit stop and go traffic again. The gauge didnt seem to get as close to the right line but was still reading about halfway between the left and right lines. Once I finally got the truck parked is when this picture was taken.

Would you consider this "normal"? My 68 dart does not have this type of fluctuations with this type of driving



for further reference, I consider normal range on this gauge to have the needle hovering over the left line with being a little to the left of it. or thats where it stays on high way driving. Before I changed the thermostat the needle was to the right of the right line. The gauge does not read that high when it has been running and you shut the truck off, let it sit for a couple minutes and start it up again. Hence why I changed the thermostat. It didnt get that high today, but it is still higher than it was before I switched to this 7 blade clutch fan (it originally came with a 5 blade clutch fan on it)
 
Update:

The changed thermostat does not do much. I am in the process of flushing out the coolant system with one of those cleaners/flushers from a parts store. Running a little cooler but not much. For what ever reason the truck likes to heat up when moving, stopped in traffic or just looking at the gauge. BUT when it is idling in park or neutral in the drive way the temp goes down to the normal spot on the gauge. Where as the fixed fan would cool while moving, but heat up in traffic and when idling in park or neutral. Still not to sure what the cause is.
 
carfreak6970 said:
Update:

The changed thermostat does not do much. I am in the process of flushing out the coolant system with one of those cleaners/flushers from a parts store. Running a little cooler but not much. For what ever reason the truck likes to heat up when moving, stopped in traffic or just looking at the gauge. BUT when it is idling in park or neutral in the drive way the temp goes down to the normal spot on the gauge. Where as the fixed fan would cool while moving, but heat up in traffic and when idling in park or neutral. Still not to sure what the cause is.
Click to expand...


post up some good pics of your present rad/fan set up
 
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