Cooling issue

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6pkScamp

6pkScamp

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What kind of cooling system are you guys running on your stroker motors? The old Be Cool rad I had with the 340 ain't cutting it with the 97 degree heat and the new motor. It runs 195 until you stop at a light and never recovers. Runs up to 210.
 
Assuming the engine is in tune, IE enough timing, You.....do....not...have....enough airflow
 
let's see a picture of your set up. Including radiator, fan, and shroud.
 
Looks like way too much rad surface being blocked by the fan mounting/shroud. This blockage would be a real issue if cruising.

If you stop and let it idle for say, 10 minutes, after it gets hot, do the fans run and does it gradually cool down?

What is that shroud off of?

And is there any rubber seal between the top of the rad and rad support and the hood?

And the core looks rather thin....
 
nm9stheham said:
Looks like way too much rad surface being blocked by the fan mounting/shroud. This blockage would be a real issue if cruising.

If you stop and let it idle for say, 10 minutes, after it gets hot, do the fans run and does it gradually cool down?

What is that shroud off of?

And is there any rubber seal between the top of the rad and rad support and the hood?

And the core looks rather thin....
Click to expand...

No it doesn't cool down and the fans continue run. Their on at stat set at 180. The shroud is off a late model camaro. Forgive me but it was a nice fit. The holes I put in there to help at cruising speed.
 
I think that your fan shroud is part of your problem. It blocks air from coming through the radiator except where the fans and "holes" are.

A fan shroud is like a nozzle that directs the air so the fan pulls it through the radiator. It must not block airflow. OEM manufacturers today put foam and rubber seals around the shroud so that no air can go around it, but THROUGH it and pass through the radiator fins. You have to keep the air from going AROUND the radiator, that's why they put foam and rubber seals to keep the air from leaking around the shroud and radiator. The shroud should direct the air coming through the radiator to pass through the fan.

Mechanical fans are more efficient than electric fans. Have you considered trying a mechanical type fan and a shroud that fits better?

Look at how they did the fan shroud on this mid 70's Monte Carlo. Look how long it is. Notice how it takes all of the air from the radiator and narrows it down so the fan pulls it through the shroud.

View attachment 197x Monte Carlo C04 B.jpg

View attachment 197x Monte Carlo C05 B.jpg


Fan placement in the shroud is also important. There is a spec in the auto industry called FOOS (Fan Out Of Shroud). It is how much of the depth of the fan is inside the shroud and how much is outside the shroud. Typically you want 50% +/- 20% of the fan covered by the shroud. This helps the fan pull the air through the radiator. Start at 50% (half of the fan depth inside the shroud opening for the fan, and the other half on the outside).

Your shroud blocks the airflow where the fans aren't. Then the holes in it, do nothing for your overheating at idle. They only let air come through the radiator when you are moving and get the "ram air effect" through the holes because the car is moving. Then where there are no holes and no fan, the shroud blocks the airflow through your radiator. You are not using your radiator efficiently.

A good shroud will prevent any air from "leaking" around the radiator, and direct it through the radiator and to the fan. I feel that your shroud is blocking more airflow through your radiator and is limiting the radiator's ability to get rid of the heat due to not enough air flow. I think that your radiator is fine, I would make a more efficient fan and shroud set up.

I would also put more "taper" in the shroud so it is not like a brick wall stopping airflow. Taper it so it directs the air to go to the fan.

In short, I feel that your shroud is handicapping your radiator's ability to do it's job (it prevents alot of air from going through it). You need a more "airflow friendly" fan & shroud set up. Maybe you can make a better one for your electric fan set-up or change your fan and shroud to be more efficient.
 
Here's some pictures of fan and shroud set-ups for you to see.

Here is an electric fan set-up for a 98 Grand Cherokee 5.9 L. Notice how it has openings in the shroud, but when put right side up, they block air flow from going through the shroud and direct it to the fan opening.

Here it is right side up:

View attachment GC Rad Up A01 B.jpg

Here it is up side down. Notice how the rubber seal flaps will open up. This lets the air flow through when the vehicle is going down the road.

View attachment GC Rad Dn A02 B.jpg

Here is the side of the shroud that goes toward the radiator right side up:

View attachment GC Rad Back A01 B.jpg

Here's a shot of my fan and shroud from my 98 Chevy truck. Notice how the shroud directs the air so it goes through the fan opening. Also notice that the fan is partially covered by the shroud, and some is outside the shroud (FOOS).

View attachment Truck shroud A03 B.jpg

Here it is from another angle:

View attachment Truck shroud A02 B2.jpg

I hope that this helps.
 
210 is not even boiling yet, but.....I understand. You wanna probably maintain 180 if at all possible. Like was mentioned, those metal shrouds tend to block the natural airflow at speed. I'm not too wild about them for that reason. I like the large single fans mounted on the backside of the radiator, like KrazyKuda showed.

First thing I'd do is to install a large engine oil cooler though too.......you've got a lot more cubic inches struggling to dissapate heat through the same sized cooling passages. You're going to wanna get creative and pay attention to all the little details. I'd also sh** can the trans cooler too, if it's tapping off the bottom tank (run a dedicated cooler for it too).
 
cudavert said:
Like was mentioned, those metal shrouds tend to block the natural airflow at speed.
Click to expand...

They also block airflow standing still at idle.


You usually get better cooling at road speed, as the ram air through the radiator helps with the airflow to cool the fins. It is more of a challenge to keep it cool when standing still at idle, with no ram air going through the radiator. That's why you need to seal the shroud so it pulls air through the radiator.

When I worked in climate control, we had to work with the engine cooling group to get the proper performance from the heater and A/C and also not overheat the engines. We did some severe testing to prove out our designs.

One test was to pull 5000 pound trailers through Death Valley with the A/C cranked. There is a sign that says to turn off the A/C through Death Valley as it is so hard on the cooling systems, that many cars overheat there. This test helped prove our "down the road performance".

Then another test we did at the proving grounds was to park the car less than a foot from a brick wall and let it idle for over an hour to make sure that it doesn't overheat. This is where you see how well your fan and shroud are working with the condenser and radiator.
 
Looks like it might be a 22" style 2-row radiator?

Might want to check this topic out.
http://www.forabodiesonly.com/mopar/showthread.php?t=287386

A 26" style radiator with the contour fans should have no trouble keeping it cool. My 26" three row champion + the contour fan easily keeps my 470hp 340 cool. The fan is off the entire time the car is moving over 10 mph.
 
So all the OP has to do is put some soft flexible rubber flaps over those big holes in his shroud and it should make a difference correct??? That's assuming he plugs all the spaces around the perimeter of the shroud where it contacts the outer edges of the radiator!!

Treblig
 
Treblig said:
So all the OP has to do is put some soft flexible rubber flaps over those big holes in his shroud and it should make a difference correct??? That's assuming he plugs all the spaces around the perimeter of the shroud where it contacts the outer edges of the radiator!!

Treblig
Click to expand...

No, it is too flat and is like a brick wall. I would "taper" it so it directs air toward the radiator similar to a funnel.

Air flow likes to go better in a straight line than turning hard corners.
 
krazykuda said:
No, it is too flat and is like a brick wall. I would "taper" it so it directs air toward the radiator similar to a funnel.

Air flow likes to go better in a straight line than turning hard corners.
Click to expand...

I understand what your saying. I'll be looking into something different. What I have came off a a big block duster and was free. Time to step it up.
 
krazykuda said:
No, it is too flat and is like a brick wall. I would "taper" it so it directs air toward the radiator similar to a funnel.

Air flow likes to go better in a straight line than turning hard corners.
Click to expand...


Sorry, I worded that wrong.


It should direct the air toward the fan similar to a funnel. Not toward the radiator. The "open end" should be toward the radiator, and the taper/funnel towards the fan.
 
6pkScamp said:
I understand what your saying. I'll be looking into something different. What I have came off a a big block duster and was free. Time to step it up.
Click to expand...

Good. I was hoping that I wasn't confusing anyone.

With how much the air is blocked by the shroud, you are not able to use all of the available cooling area of the fan.


Also keep in mind that the key is to get airflow through the radiator. Area has more benefit than depth. Depth adds resistance to airflow, area doesn't. If you have a choice. go with more area over depth, and add depth if you don't have any more area. The thinner the radiator, the easier it is for air to pass through it.
 
6pkScamp said:
I understand what your saying. I'll be looking into something different. What I have came off a a big block duster and was free. Time to step it up.
Click to expand...

You don't need to "step it up". That's what gets so many into trouble. You need to "step it back". Back as in how the factory did it.
 
Here is my opinon. Are you using a tranny cooler? That too could be blocking the air flow. I am not a big fan of electric fans. I once had a heating issue where my engine would run around 210, with a tranny cooler, just a little warm for me. I removed about .750 off from my fan spacer which allowed my fan to be further back from the radiator allowing more air flow over the entire radiator. I also added a shroud in which I had to modifiy the brackets in order for it to fit and I have had no further heating issues. Car runs around 180 and in traffic it doesnt go above 190. Up here in North western Pa the weather temp does tend to get a little on the warm and humid side...
 
6pkScamp said:
The 340 never got over 180. Everything else is the same
Click to expand...

Same block? If not did you clean the bare block picking the scale out of it with coat hanger/picks/etc? Same over-bore?

Are those billet underdrive pulleys? Did the old motor have them. I'd go back to stock ratio.

The whole electric fan thing gets you into trouble. I was ok with 4 row champion and stock fan even without a shroud and a large trans cooler in front of it on my 416 stroker .
 
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