Cooling issue

[cee21]

Ok, I finally got freon in my a/c. Before that, it ran fine right between the O and R in NORM (N is at the top near Hot and M is at the bottom near Cold). Well it would run fine with the hood open just idleing, but when I close the hood it gets up to the N (all this is with a/c on). If I turn it off it will start to cool back down. If I drive down at highway speed it SLOWLY starts to cool back down. When I was coasting down a hill doing about 47 it only cooled off when I reved the motor up about 3 times. My set up is 2 10 in. pushers and 4.0 explorer rad. The truck is a 84 and has the original hood insulation. Will removing the insulation help, or will that hurt the paint? My paint is clear coated. And I have not made shrouds for it yet, would that help that much?

[cgrey8]

The hood insulation is much more for sound dampening.

As for the cooling, if you don't have shrouds around the fans to direct as much of the air into the radiator, you could easily have cooling problems. I'm running 2-12" fans and I closed as many of the air-gaps as I could. I used foam between the condenser and radiator to seal up any blow-around since there's a fair gap between them. I also sealed up around the condenser and the body as best as I could. But the biggest thing I did was install sheet metal shrouds under the fans so the gaping holes my Ranger had below the pusher fans didn't allow the pushed air to blow back forward instead of being forced through the condenser and radiator. Even though the truck didn't have a cooling problem before, putting those on made a noticeable difference in how long the fans had to run to cool the motor.

Now if you have puller fans on the backside of the radiator, then you'll need a shroud so the fan isn't pulling through only an area of the radiator the diameter of the fans. Putting a shroud in will allow the fans to pull air from the entire area of the radiator...very important.

Finally, if you have Flex-A-Lite fans, that could also be part of the problem. PermaCool fans flow nearly twice as much as a Flex-A-Lite of the same diameter.

[cee21]

My fans are from a local performance shop that claimed they pushed 1300 cfm each. They are the curved blade design, I am begining to second guess them. They just said they get it from a manufactorer but never gave me a name. Probably a big mistake on my part. I will see if removing the insulation will help first. I remember you saying you used foam before, what kind was it exactly, expanding foam, tape foam, etc.?

[cgrey8]

I seriously doubt the insulation is going to make a bit of difference. My truck has insulation in the hood, and I've never had a cooling problem with it at all.

As for the foam, I used tape-foam. In specific, its the foam you put between a camper shell and the bed rails on a truck. I layered 4-6 layers of that tape foam together to get the thickness I needed and then stuck it between the radiator and the condenser with the radiator unbolted and pushed forward (toward the motor). Once all the foam was in place, I pulled the radiator into place which compressed the foam to make a seal and bolted it in. I couldn't get the bottom sealed up so I used Great Stuff and squirted it in below the radiator. It expanded to fit the area and because it was on the bottom-side, it isn't readily visible from above so I didn't mind using it. I wouldn't recommend using it anywhere else though...that stuff is MESSY.

[broncobowsher]

Hood insulation is noise abaitment. Leave it.

How well does the fan shroud seal up to the radiator? Do you still have all the original trim pieces in place to keep the air flowing through the radiator and not around it?

[v8ranger]

Do you have under drive pully's? if its only running hot at idle its sounds more to me that its not surculating fast enough. Just a thought