I hope to start on my 69 F250 CS this winter. I'm going to remove the front clip, radiator, and the stock exhaust manifolds. I have an entire 79 front suspension , new brake lines, new column, inner fenders, headers, and hopefully an alum 4V intake (to fit the summit 4V carb I got last year) to install. I had the original radiator cleaned and repaired two years ago. The repairman said that the bottom was very thin, and I should get ready to replace the radiator. So should I stay with the original flow type, or change over to a "cross-flow type. Either type that I get, I think that I should go with aluminum. What are your suggestions and ideas?

 

I'd go with a regular up-down. Either a 3 row, or 2 row "jumbo". Depending on what you think would be more suitable.

 

Yeah, I was leaning towards a 3 core. With both flow types being aluminum, does one type cool better than the other?

 

Gary,
I bought this stuff for my 71-CS/250. Haven't installed it yet though.
https://www.jegs.com/i/Champion-Cool...CC433/10002/-1
& this fan.. https://www.jegs.com/i/Speedmaster/7....1010/10002/-1
& this fan wiring harness.. https://www.jegs.com/i/JEGS/555/10560/10002/-1
& this waterneck.. https://www.jegs.com/i/Trans-Dapt/969/9524/10002/-1

I'm guessing I may have to fab some brackets for the radiator but that's OK by me. I'm dumping the factory fan and spacer that bolts to the water pump but keeping the pulley.

Dan

 

Dan, that's a nice set-up, and a good price too. I will look into that one. Now I have to figure out how to I tell the CFO that we need a need one. Wouldn't the straight blade fan be a bunch louder than a curved blade unit?

 

 

Gary,
I honestly don't know. But I also punched the motor to a 418ci, dynoed at 370hp with roller rockers/cam with Sanderson headers blah, blah and figured I'd hear that racket and didn't care what the fan was doing as long as it cooled. I ORIGINALLY had the Factory HD radiator that had the oversize inlet but it was stolen so I bought the new Aluminum one and removed the pump mounted fan.

Now if you want to buy a really nice brand new motor, rad, fan, wiring, I have a 71CS that's really clean I'll throw in with it...

Dan

 

Top-down coolers perform better than any sort of cross-flow cooler will, but they come at the cost of lower aesthetics and occupying more real estate. Neither one will give you issues, but I'd stick to a factory style.

Copper actually conducts better than aluminum but it weighs more and costs more.

I prefer electric fans but no matter what fan you go with, your cooling system will never perform optimally without a fan shroud. You'd be amazed at how critical this very simple component is to the cooling system.

As for coolant, I use the highest ratio of water possible for my climate as water conducts better than coolant does. I also use water wetter to help eliminate bubbling, take away surface tension from the coolant, and add additional water pump lubrication.

 

Thanks for "the offer" Dan, but I'll stick with what I have-for now-LOL.
Good to know that, "65Ford". Wow, 5 ton towing!! I don't plan on anything like that. I plan on using it as a light duty work-around-the-house truck. I already have a shroud.
"trozei", thanks on the info about which flow type cools better. I'll stay with the top-down style. I thought that aluminum cooled better? Isn't that why the pros all use them? I do plan on going to elec fan set-up. I have to do the 3G swap on this truck yet. I did it on the F350 that I had. Easy swap with great results.

 

Aluminum has only 30% of the weight of copper. The "pros" whoever they may be are more interested in not having a boat anchor on the very front of their vehicle. Aluminum is lighter, costs less, doesn't corrode, and is obviously more than capable of doing a good enough job, which is why all the OEMs and pros use it. I also don't know of many companies making copper radiators.

 

Very good point about the weight and most likely the cost of copper limits the OEM people from wanting copper. Thanks again.

 

I can't agree that a down flow will cool better. All else being equal (surface area, material, construction) they cool the same. The only real advantage of a cross flow is hood clearance and the ability to run a multi-pass radiator which is overkill in most situations.

As far as aluminum vs copper, copper is a better thermal conductor but the name of the game is surface area, and you can't build a radiator with wide 1 1/4" tubes out of copper. I prefer a copper core in applications where their cooling capacity is adequate, but a single or double row aluminum will out perform a 3 or 4 row copper because of the greater surface area of the tubes and less airflow restriction.

 

Hood clearance, cost effective, and ability to handle 16# of pressure rather than 13# are why the Manufacturers use them. That 3# of pressure are the only thing IMHO why a cross flow could cool better than a brass one. 3# raises the coolant boiling point a bunch.

 

The added pressure also serves to force the flowing coolant up into the nooks and crannies and tighter up against the odd rough cast surfaces of the coolant passages in the block. Which should all allow more consistent cooling throughout.
More water pressure is a good thing inside an engine. Reduces the ability of steam pockets to form around air bubbles or exposed surfaces that are allowed to cause localized overheating. A very common problem with over-bored 351Windsors in fact.

If you've ever seen LS engines with the tops off of them, GM uses "steam tubes" crossing over between different parts of the block to reduce that effect another way even more. There used to be (maybe still are) cross-over tubing kits for 351w engines to reduce this too.
Add that to the higher boiling point and good things happen.

Paul

 

Yeah, I knew about the pressure difference and the bennys from it. I've been looking at a "Champion 3 core" (Part Number: 166-CC433) It says it comes with it's own radiator cap,but I didn't see anything mentioning the pressure amount. I'll have to call for the spec.s . High volume water pump is next item that I researching. So far, it looks like Summit has the best price.