Hornman wrote:
TKOPerformance wrote:
20" copper/brass three row, 180 t-stat, stock parts store water pump, SPAL fan with a controller I built. Hottest I've seen it get was 210 when it was in the high 90s with high humidity and a heat index well past 100. When I finally get to the AC I will be going to an aluminum radiator and I do not expect anything will change cooling wise. The copper/brass just can't reject heat as well as aluminum.
This is a good time to remind everyone why the factories used copper radiators for so long. Copper transmits heat nearly twice as well as aluminum. The reason aluminum radiators are popular is price, you can buy two, maybe 3, aluminum radiators for the price of one copper radiator .
If you are running a small Windsor and your cooling is marginal, it’s possible you could solve the problem by installing a four row stock style copper radiator. Of course, that copper radiator will cost $500-600.
One other factor in the copper vs aluminum choice for radiator material is that copper is significantly more corrosion resistant than aluminum. In fact if you are running an aluminum radiator you should also be running a magnesium sacrificial anode in the aluminum radiator.
Copper does conduct heat better than aluminum (about 100% better), but that's only half the story, because copper radiators aren't all copper. They are soldered together with lead, which is horrible at conducting heat (less than 10% the thermal conductivity of copper). They have steel side channels (a bit more than 10% the thermal conductivity of copper), and brass end tanks (about 25% the thermal conductivity of copper). Its therefore tough to say how good a copper/brass radiator is from a thermal conductivity standpoint, because you have to look at more than just the difference between copper and aluminum for the comparison to be accurate.
This is also a largely irrelevant consideration because cooling to a large extent comes down to surface area. Copper/brass radiators use 1/2" tubes where aluminum ones use 1" tubes. From a surface area comparison a two row aluminum radiator with 1" tubes has the same surface are as a 5 row copper radiator with 1/2" tubes. This higher surface area also exponentially increases the fin to tube contact area, which is a direct measure of a radiator's ability to radiate heat. Finally, aluminum radiators use a 3/8" tall fin vs. a copper radiator's 1/2" tall fin, so in a radiator of equivalent size the aluminum radiator has significantly more fins in each layer of the core.
In summation, though aluminum may be less thermally conductive than copper; aluminum radiators significantly outperform copper radiators of the same size, regardless of the number of rows in the copper radiator's core, because of the design differences in the way the two types of radiators are built.
Compared to an OE aluminum radiator with epoxied on plastic end tanks I must give the edge to copper/brass in terms of longevity. BUT an aftermarket aluminum radiator that is fully welded will not have this disadvantage. I've also always had factory radiators of the plastic/aluminum type go at lest 7 years, and the cost of replacement is fairly low (the one for my F250 Diesel was less than $200).
Aluminum is more likely to be corroded by coolant that has been allowed to go acidic, but this is also going to effect your timing cover, intake manifold, cylinder heads, water pump, and any other aluminum part in your engine. A sacrificial anode is not a bad idea regardless of what type of radiator you run, and its also a good idea to change your coolant regularly to prevent it from becoming acidic.
Last edited by TKOPerformance (7/20/2019 5:01 PM)
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