Radiators = new vs rebuilt

[imiceman44]

Actually, Copper has a much higher heat conductivity than aluminum does; 400 W/mK versus 255 W/mK. Aluminum conducts less than 65% of the heat that copper does. The reason most rads are now aluminum is simply due to cost. When I replaced the rad in my k5 last year, I bought a spectra premium brass/copper rad. It was about $100 more than an aluminum/plastic rad, but well worth it imo. I looked into rebuilding the factory rad, but there was not much difference in price, and the tanks on mine were kind of beat up.

Conductivity is not what a radiator needs, it's heat dissipation, and that is what aluminum does better. That is why most if not all heat sinks are aluminum.
That is why aluminum radiators cool better with less rows.
Actually if you could make a single row you could get better heat dissipation per CI because the hot air doesn't hit the second layer.
That is why 4 row radiators do not cool 25% better than a 3 row.
Copper has one advantage though, it's easily repairable with common tools, aluminum and plastic not so easy, and not everything is repairable.
I have repaired a copper radiator that was smashed in an accident, even the tanks were messed up and I took it appart, straightened the tanks, welded the broken parts, and then sealed the few parts of the core that busted open and I had a decent radiator to get me home.
Can't do that with a plastic/ aluminum radiator.

 

[groovy75]

How do you tell if its a true copper radiator? Someone offered me a free old radiator today and on the top output it had a shiny brass/cop material under the paint where it was scratched off on the upper outlet where the top coolant line hooks to, but the fins looked aluminum so I didn't take it. New stock?old stock? He counted the cores and it had 3. How do you spot a copper radiator? I've never seen a 100 % copper radiator before.but that dosent say much because I'm fairly new to knowing my radiators. Iol

 

[swettysblazer]

A copper/brass radiator will GENERALLY heavier than an aluminum/plastic one. I am not saying this is true in all cases, but if the sucker has some weight to it it is most likely copper and brass. Try and post a picture up

 

[K5dreamer]

YO - love the setup. Id love to ditch my V-belts and clutch fan for a serp setup and electric fans on my big ol monster copper/brass radiator. if i ever find a trunk at the junkyard with a 6.5 TD in it... hell if its a 1993 id probably just get the whole engine, but i digress

 

[groovy75]

In the end I just went with an el cheapo from kragens,and it works great!