radiator & fan thoughts

[Gunnibronco]

Its time to break down and replace my old radiator. Its leaking from a few spots & I'm having trouble keeping the temps down. Especially when idling on trail runs. Currently, my radiator is a 4 core, probably JBG, from like 12-14 years ago. One of the first repairs I made. About 5 years ago, I replaced the stainless flex fan that came on the truck with a fixed blade fan.

I think I'm going to stick with the copper/brass radiator, but I'm wondering if I need the 4 core I've got. Is anyone else running a 4 core, or had a 3 core that wouldn't keep up? I'd like to save the money and get a 3 core if I wouldn't have to worry about having to upgrade back to a 4 core.

My other thoughts are on fans. I found a CB.com discussion about a Hayden clutch fan that fits a stock v-belt set up. I took some measurements and think I'll have no problem fitting it behind either 3 or 4 core radiators.

Would the clutch fan be a better choice than an all electric set up? I've read about the Taurus fans & have another possible donor fan/shroud at work right now. I've got a 200amp alternator, so power isn't a problem. But I think, the time spent modding fans & the money spent on the relays, etc might not be worth it. When a clutch fan is available for like $70.00. Anyone running an all electric set up & love it/hate it? Any thoughts are appreciated.

If I go with the clutch fan, I'm planning to put an electric pusher fan on the front. After this weekend on Chinamen's I love the sound of an electric fan running after the truck shuts off.

Thanks
Chad

[Viperwolf1]

A clutch fan, properly spaced in the shroud, will pull more air than most electric fans. If it fits with your 4 core radiator just get it fixed. Even tiny leaks will cause high temps.

[Gunnibronco]

I'm not sure how easily I could get it fixed. There is no one in Gunnison who does radiator work anymore. Its not in great shape either. Its leaking where the finned tubes enter/exit the tanks, on both sides, and some of the front tubes are smashed from body flex, probably from last weekend. It almost looks like it would need recored. One of the mounting brackets broke free from the tanks too.

Chad

[Gunnibronco]

Did a lot of shopping, locally & on-line today. 3 core copper/brass rads ranged from $200.00 - $300.00.

I ran across a vendor on Amazon.com called Oconee4x4, they list a 4 core high efficiency for $299 + shipping. I went to their web site (oconeeoffroad.com) and found the same rad on sale for $269 with free shipping, with an additional 5% discount applied it came to $255.54. I went ahead & pulled the trigger.

Chad

[Gunnibronco]

Will do. Kinda stepped out on a limb, buying from an unknown company, but JBG wants $330 + shipping for a HE 4 core. Got one with the a/t cooler, so I can change transmissions later, same price.

Chad

[Jesus_man]

I think you are smart to get the 4-core. Better to have too much than too little. Let the thermostat do it's job. Oconee sounds familiar to me, but I am not sure why. Maybe that's where I bought my heep mirror from.

I have a solid fan and have been happy with it. One nice thing about a properly sized electric is that it can flow more air when you're at low rpms crawling since it's not related to rpms. The sound for me is a tiny bit annoying because I've had to try to talk over several before and really, it's not doing much simply because the water is not circulating. But there are some quieter ones that aren't bad.

[Gunnibronco]

I think you are smart to get the 4-core. Better to have too much than too little.

I had a hard time coming to grasp with "downgrading" from a 4 core to a 3 core, even though a 3 core is probably adequate. I'm used to making upgrades to the Bronco, not the other way around. It really can't hurt to have too much water & cooling surface area. Its not like I'm running an A/C condenser in front of the radiator too.

I'm going to install the new rad as soon as it arrives, probably with the existing fan. After the old rad is out I am going to play with my Kia Borrego electric fan. It's a 20", 2 speed fan, for a 4.8L V8, it really pumps some air on high speed. IF I can easily mod it to fit my rad, I'm going to try using it. If it doesn't work, I'll go to a clutch fan. I kinda just want to see if I can do it. And it will be funny to answer "it's a Kia fan" when someone asks about it. If it works I'll install it when I rewire the truck, the next step before going EFI. Regardless, I'm going to spend some time making baffles & seals to make sure the fan is pulling outside air, not under hood air. There is a lot of room for improvement there.

Chad

[Justin]

I'm not sure it's much of a downgrade. My understanding is that the 4-core doesn't cool much better than a 3 core since it is tougher to cram air through the thicker radiator.

[Gunnibronco]

I'm not sure it's much of a downgrade. My understanding is that the 4-core doesn't cool much better than a 3 core since it is tougher to cram air through the thicker radiator.

I think that fact is still up for debate. If that were the case, no air would ever get to a rad in modern diesel truck. You should see the stack of coolers in front of the radiator- p/s cooler, a/t cooler, a/c condenser, & turbo intercooler. You are right that it isn't necessary with a 302 if everything else is in good working order, but it can't hurt. You are increasing coolant capacity & cooling surface area. I did read that the fit between a 4 core, core and the 3 core tanks leaves these prone to early failure.

After 15 years in pool boiler installation & repair, I bet water flow is the most important factor. We would tune a boiler, by slowing down the water flow through the boiler, so it would maximize the amount of heat it picked up. In reverse, you could figure out how to tune the water flow to stay in the radiator the "perfect" amount of time to dissipate the most heat. Maybe that is why some people claim a 195 thermostat helps them stay cooler than a 180.

Chad

[Gunnibronco]

I think Chad is closer to right on this but anything is possible in each situation. If you have too much air flow past your coils you will not take the differential heat transfer off the radiator/fluid that you should. It needs to be balanced for each situation. Same goes in the HVAC trade when dealing with heating coils and A/C coils. If the air is going through the radiator too fast it wont grab the heat off the radiator like it should making it ineffiecient, same goes for too much or not enough coolant flow. Thats also a reason why some people have issues with high flowing water pumps and their rig is still hot.

Makes sense to me, it is another reason why blanket rules are not always true, something may have an unintended consequence. Each system, in custom rigs like ours, is its own unique monster, too many variables - different radiators, water pumps, fans, general condition of engine/cooling system, etc - to KNOW what is best for everyone. After typing my message above, I realized a high flow water pump really could cause your temps to raise, if the water wasn't in the engine or the radiator long enough to capture, or release enough heat. I guess, even too much fan could move the air past the rad too quickly, therefore a smaller fan or a fan moving more slowly could reduce temps.

Crazy to think about, kinda all theory without proper measuring tools. You'd really have to test water temp loss & air temp gain through the radiator to actually know what to do. But you could fine tune water speed/volume and air speed to an ideal, if you wanted to. We've got a digital IR thermometer at work, I'll play with it as I make my changes, but I'm not even sure that I could accurately measure air temp, maybe just the inner & outter surface temps of the radiator & inlet/outlet hoses.

Chad

[Gunnibronco]

Makes me think that the best radiator, regardless of number of cores, is the type sold by WH as "Tripple Pass", BC has their own (crazy expensive) version too. Helps maximize the path & length of time the water is in the rad.

Chad

[ZOSO]

Also the right temp t-stat. I run a 195 and never have an over heating issue. Same with my dads 74 with the 351.

[Booger]

Makes me think that the best radiator, regardless of number of cores, is the type sold by WH as "Tripple Pass", BC has their own (crazy expensive) version too. Helps maximize the path & length of time the water is in the rad.

Chad

All the reading I was doing about this several years ago led me to the same conclusions. I myself want to replace my radiator with the triple pass one. A little longer in the radiator and it cools better.

[Shawns Fords]

I had the issue with my old Radiator in my 81 F250, leaking at the top side of passenger tank. I went to the yard and found one that was in near new condition out of a later model (1984) which had an aluminum cross flow. 65 bucks and I only had to drill two holes to make it fit because the mounting locations were changed on top. just an idea but it might not be a bad idea to just take a look. I saw several other decent radiators down there that day. Took me a total of about 2 hours tops.

just a thought.

I also would run a fan clutch unless your looking for the most efficiency out of your mileage. Or if space is an issue. I ended up with an electric fan on my 460 because there really was no room for a clutch and fan up there and I didnt want the extra load on the drive pulleys.

[Gunnibronco]

The company has already shipped the radiator out, not bad. They stated that the radiators might take 1 week to ship, so they are already ahead of schedule. It shipped out of Laredo, TX, if that means anything to anyone. The company in Georgia is obviously buying them from someone else. We'll see how it looks when it arrives, its scheduled to hit on Monday.

I think my biggest concern is how long it will last. Seems like a common problem to have the 4 cores leak. Mine has been leaking for a couple years, but, it lasted 11 years. I found my receipt from 2000 for the radiator from JBG. Only $195.00 back then.

Chad

[Gunnibronco]

Radiator arrived today, nicely packaged, lots of InstaPak foam protection. You'd really have to try to screw up the radiator. Everything looks good. I don't know what a High Efficiency core looks like compared to a standard core, but I don't see a big difference between this one and my old one. I haven't compared them side by side yet. Hecho en Mexico.

Chad

[Gunnibronco]

I put the radiator in last Friday. Went in just as expected, no troubles.

The core on the new rad is thinner than the old JBG rad I removed. I installed 4 core rad brackets when I put the JBG rad in 10 years ago. The new rad was a bit loose in the mounts, but nothing a little adjustment couldn't fix. It would probably fit in standard 3 core brackets. Hopefully this means the fit between the tanks & core is closer to original, maybe meaning a longer life. Only time will tell.

This new rad has more sets of tubes than my old JBG rad (49 vs 42) & more fins/inch (8 vs 6). Just to split hairs.

I took my old radiator & checked out the fit to the Kia Borrego fan I have, and it doesn't look like its worth the effort. So I'll probably be upgrading to a clutch fan & maybe adding an electric pusher. I'm also going to take some time to dam off the air to make sure the rad is pulling fresh air, and not hot engine compartment air. Seems like time well spent.

Chad

[Jesus_man]

Good to hear install went well. My cousin just tested out his new radiator after having overheating issues for a long time and it performed well. Hope yours does too!

J.D.