Radiator Re-Core - 2 or 3 Row?

[justincollier]

I just heard from the radiator shop and they confirmed what I feared, the core is rotted on my Barracuda. Good news is that the tanks are fine. I think I'm going to bite the bullet and have it re-cored. So I'm seeking advice of which direction to go.
Here are the relevant facts:
-1972
-26"
-Original stock 340
-Automatic
-Factory A/C, which I'm in the process of restoring and plan to use.
-I'm in Missouri, so it gets hot, but not desert hot.
The radiator shop said it is currently a 2-core. He said he could fit a 3-core in it if I wanted to go that route. Price is about the same, but is there a benefit of moving up to a 3-row? This is a driver/cruiser, so it sees a lot of city driving. I was planning of running stock 7-blade fan and clutch, and possibly upgrading the water pump to a FlowKooler as the original has already been replaced.

[pschlosser]

I vote 3-core.  They cool better than 2-core.  26-inchers are well accepted as cooling adequately.  But there is no harm in upgrading the radiator so it's capable of over-cooling.  The thermostat keeps your engine from over-cooling.  Many of us with 22-inch radiators must often go to 3-core just to keep our cars from over-heating.  Factory A/C will also heat things some.  So go with a 26-inch 3-core and you wont be sorry.

[Mrbill426]

I vote 3-core.  They cool better than 2-core.  26-inchers are well accepted as cooling adequately.  But there is no harm in upgrading the radiator to it's capable of over-cooling.  The thermostat keeps your engine from over-cooling.  Many of us with 22-inchg radiators must often go to 3-core just to keep our cars from over-heating.  Factory A/C will also heat things some.  So go with a 26-inch 3-core and you wont be sorry.

[JS29]

    :iagree:X2   

[justincollier]

Thanks for all of the input.
My only concern was if the radiator could hold more coolant with a 3-row, would I be able to move enough air across it with my stock fan and shroud?
My guy doing this has probably been in business 40+ years and has done several radiators/fuel tanks for me over the years. He's about as honest as they come, so I'll add his opinion into the mix before making a decision, and follow-up here.

[Mrbill426]

You should be fine with both. If everything is stock you already have a good fan and shroud with your factory A\C. Just make sure your fan clutch is good too.

[MoparLeo]

There is more to it than just how many rows there are, fin count spacing is more important for heat transfer. The more fins per inch as a rule means more cooling. Of course the quality is where the real difference is. The better and closer the fin is to the cooling tube the better. This is where most brass/copper cores lose their edge. bad joints and/or too much lead in the fin/tube contact area lowers cooling efficiency. This is where the OE aluminum cores catch up in efficiency to the old style but at a lighter weight and lower cost.

[blown motor]

I have a stock 26" 3 core in my 74 with a 340 but no A/C. Cooling is awesome. Go with the 3 core.

[justincollier]

@MoparLeo
Thank you. Very helpful information. I found this article, which is what you are saying and the exact questions I need to be asking my radiator shop.

https://www.hotrodhotline.com/content/aluminum-vs-copper-brass-article-us-radiator

[chargerdon]

My 74 chally 318 factory air, originally came with the 22" radiator which is long gone.   So, i needed a new one, and new that a 360/408 with Vintage air would need a good cooling system.   So, also being cheap...i looked long and hard...seeing prices as high as $900 or as low as $100.   Eventually, i contacted a Champion radiator reseller, who said first";

...buy a 26" aluminum as the few copper are ridiculously expensive.   

Then the question of 2 row, 3 row or 4 row...  Champion had both the 2 row and the 3 row in the 26" for small block that was the same thickness as an original so that it would fit after cutting out a couple of inches in the radiator support...   He read the specs for cooling for both to me and they were near identical...both rated to cool as much as 600 HP of engine,   Understand, that if the thickness is the same, then the tubes have to be smaller on three row to fit as compared to the 2 row...   So, with the 2 row being $50 cheaper i went with the 2 and the sales person said...absolutely same cooling rating.   

Now the results...   On the road, absolutely no problem...i run a 195 thermostat and it will vary between 190-220 always when driven.   The problem comes when idling in hot temps (regularly hits 90-95 in NC).   I have never had it overflow, but, when driving in a parade which i do couple of times a year, it will rise to 230-240 and then it starts to stumble and idle bad.     I am running a 7 blade fan which pulls air nicely...  at idle it will hold my handkerchief against the grill.      I since had added a shroud and that helps, i also reduced the amount of anti-freeze down to a 10% mixture plus a pint of purple ice anti corrosion, which then gives me a 10 degree freeze point, which it almost never drops below in NC, and if it does, i turn a heater on in my garage.   The 10 percent is because WATER is a better heat transfer liquid by itself than is Glycol antifreeze...   With these two mods, i can run the car in the parades whenever the ambient temperature is below 60...i.e. Xmas parades. 

Real question is would the 3 row have been better??   I do know that the 3 row uses smaller tubes, and is the air flow worse for the middle row ???   This is not a simple question of if 2 is good wouldn't 3 be better ??    Ill never know..   Would love to add in a PUSHER electric fan to help, but, the room between the AC condenser and the grill is kinda prohibited, and i do NOT want to remove the stock water pump fan...   Im looking at putting in a couple of 7 inch pusher fans with a manual switch on it for the parades.   

[blown motor]

My 74 chally 318 factory air, originally came with the 22" radiator which is long gone. 

Are you sure? My 74 318 factory air car has a 26" rad. It's my understanding that all A/C cars got a 26" radiator. I believe my rad to be original but I don't have a fender tag.

[YellowThumper]

My 74 chally 318 factory air, originally came with the 22" radiator which is long gone. 

Are you sure? My 74 318 factory air car has a 26" rad. It's my understanding that all A/C cars got a 26" radiator. I believe my rad to be original but I don't have a fender tag.

Wondering out loud, is the 22" radiator and a/c a manual trans car? That may also impact the option.
My 74 318, no a/c but with 3spd manual actually came with factory with a 19" radiator. Fits same hole as the 22" in core support. It had a wide bracket to take up the difference.

[blown motor]

Interesting. I didn't know they made a 19" rad.

[YellowThumper]

Interesting. I didn't know they made a 19" rad.

Yep. Bolts into stock 22" location.

[chargerdon]

My 74 chally 318 factory air, originally came with the 22" radiator which is long gone. 

Are you sure? My 74 318 factory air car has a 26" rad. It's my understanding that all A/C cars got a 26" radiator. I believe my rad to be original but I don't have a fender tag.

You could be right, as my original rad is like i said long gone, and so when i was restoring my Chally obviously i had to buy a new radiator.  I was trying to answer the question of 2 row or 3 row based on the information from the Champion support person.