3 core vs 4 core radiator questions

[CopperBronco]

I’m going to be updating my radiator and coolant lines…

My ‘66 has the original radiator in it I’m pretty sure… has the cap off to the side and looks like photos of the 66’s I’ve seen. It still works, but I just don’t trust it as my temps can hit 210 idling on a hot day… doesn’t help I don’t have a fan shroud. I’m running a C4 auto trans, mechanical fan, no shroud, and a 302. I’ll be adding a shroud , came without one…

I’ve been reading threads on here and seems to be some debate about aluminum 3 core vs 4 core… that the extra thickness of the 4 core actually can harm air flow due to tight space between all elements.

Also should I worry about using a 1/2” fan spacer? Stock is 3/4”… has anyone had clearance issues issues with their belts?

Also curious does it cause problems to use a stock water pump with a 4 core radiator?

Any other concerns or things I should consider? Just trying to anticipate ripple effects and make wise decisions before making the plunge.

 

[SteveL]

My preference is the improved copper/brass 3-core like bc once had. I've heard driven auto parts still carries em. The copper/brass 4-cores dontseem to last. They like to spring leaks. The aluminum ones are more brittle and corrode easy unless You're anal about the coolant.

 

[Broncobowsher]

Fan shroud!!!! Put on a fan shroud!
You will not fix a hot idle in a Bronco without having a fan shroud.

 

[Slowleak]

I’m with Broncobowsher. If it is running hot only at idle then you have a airflow issue. You need a shroud, if that isn’t enough then maybe you need a better fan to pull more air thru. A Ford 7-blade flex fan is about the best you can get for moving air. It’s not a radiator issue. A stock radiator should work fine.
I tested fans a few years ago with an anemometer to see which pulled the most air.
Here’s what I found:
Six blade 17 in. stock fan, stock pulley - 492 ft/min
Seven blade 18 in. stock flex fan, 5.4in pulley - 846 ft/min

 

[Timmy390]

Shroud much cheaper to add than a new Rad.....

Tim

 

[Glass Pony]

I am running a 4-core radiator and still using the 3/4" spacer. 351W with a Flowcooler water pump.

 

[toddz69]

My preference is the improved copper/brass 3-core like bc once had. I've heard driven auto parts still carries em. The copper/brass 4-cores dontseem to last. They like to spring leaks. The aluminum ones are more brittle and corrode easy unless You're anal about the coolant.

Just as an FYI - Randy has closed down Driven 4x4 as we know it and moved his remaining parts inventory to his home. Still has some used parts to sell but that's about it. He stopped carrying the high density 3 cores (my favorite as well) about 8-10 years ago when his local supplier couldn't get the core material anymore and switched to using the WH staggered industrial 4 core radiators (a good one, imo).

US Radiator sells several varieties of the really nice high density 3 core radiators but they're pricey.

Todd Z.

 

[CopperBronco]

how much clearance do you need between radiator and power steering gear box? Using stock radiator mounting holes in core support I’m getting around a 1/4-1/2”… is that enough?

 

[Broncobowsher]

how much clearance do you need between radiator and power steering gear box? Using stock radiator mounting holes in core support I’m getting around a 1/4-1/2”… is that enough?

¼" would be a little tight for my liking. ½" should be fine. The body mount bushing has some give, but not a lot.

 

[CopperBronco]

Thanks! Guys at TBP said to hammer it if it’s too tight…

 

[CopperBronco]

An anyone tell me which C4 trans cooler outlet is hot and which is cold, there are two on the passenger side a few inches apart. Also… I just got Tom’s 4 core radiator, it has the two trans cooler attachments on the passenger side, one up high and another down low. Does anyone know which of those is hot vs cold?

 

[Madgyver]

An anyone tell me which C4 trans cooler outlet is hot and which is cold, there are two on the passenger side a few inches apart. Also… I just got Tom’s 4 core radiator, it has the two trans cooler attachments on the passenger side, one up high and another down low. Does anyone know which of those is hot vs cold?

they are both on the cooler side of the radiator.

 

[CopperBronco]

they are both on the cooler side of the radiator.

I guess im asking which is the return line? From what I can tell the rear C4 opening is the return and the top of the radiator is return as well, which means fluid will leave “front” of transmission to bottom of radiator up to the top of radiator and return to the “rear” of the transmission.

 

[surfer-b]

yes rear is return on the c4, I have always ran my hot line in the top of the radiator and return on the bottom, that way it will cool with the radiator coolant and have always had good results, however, some bring up Q's about air in the lines if ran this way, I have never noticed in problems though

 

[Broncobowsher]

C4 front fitting is hot oil from the converter.
Rear port is return oil to lube the back of the transmission.
That's how I always remember it.

 

[CopperBronco]

Got it, thanks… and on C4 trans cooler lines do you guys just use Teflon tape? Or some sort of hydraulic thread sealant? Looking to make sure I don’t get leaks… going to install stainless braided hoses / AN fittings.

 

[toddz69]

You can always remember the C4 this way:

Front = feed
Rear = return

Todd Z.

 

[CopperBronco]

Thanks @toddz69 … any thoughts on whether trans coolant should flow up or down the radiator or is it just a preference? Sounds like people do it both ways.


Sent from my iPhone using Tapatalk

 

[toddz69]

I think it's just a preference. As @surfer-b mentioned, some folks mention air in the lines that way but that's how the factory ran them so I tend to mimic their configuration as a default.

Todd Z.

 

[DirtDonk]

My feelings go along with the others.
In a standalone external cooler with the lines facing sideways, you would put the inlet at the bottom and the outlet at the top.
If you have a choice of the fittings facing up or down, you face them down.
But in an internal radiator cooler, you should go with the natural flow. Hot at the top cool at the bottom.