Copper/Brass vs Aluminum rad

[speedyblue]

OK, this is a bit hazy, but it's what I remember from chatting to my mate, who works for K&J here on the coast.

Copper is better than Al for heat dissipation.

Al will last longer.

Early copper radiators had inefficient fins running through the tubes, hence the Al radiator was more efficient and cooled better. A newer (better designed) copper radiator will work better than the same thing made in Al, but will be heavier.

Also to note, black is the best colour for transferring heat, silver is the worst.

Lastly, a 280zx radiator will easily fit into a 240Z, but the bottom tank will hang down by 4cm approx. I have sat in traffic for an hour in 25 degree heat with one 12 inch thermo with the temp gauge just over half way, no thermostat.

FWIW

Scott

[sblake01]

Geeez Blake....I was just agreeing with your reply regarding production aluminum radiators and adding a bit of info regarding aftermarket aluminum radiators! No need to clarify or rationalize your reply. Hope you didn't think I was trying to rain on your parade? I for one, most always respect your posts.

No Tom, I didn't take it that way. I only reposted to be clearer.

[Pavolka]

Great discussion! If you are having a problem with a copper radiator, it is probably plugged. New design copper rads with new higher efficiency cores are superior to aluminum. Aluminum gets better the bigger (more mass) it gets. For size-wise in a z-car copper will cool better. I would suggest recoring you old rad with a new high efficieny copper core. It will have louvered fins. Aluminum is used in the manufacturing process because of environmental concerns with copper (lead tin zinc arsenic) plus copper rads cost more and take more labor to put together. Aluminum cores are built and run thru a oven and plastic tanks are injection molded all in one piece. Would you want aluminum wiring in your house?

[jmortensen]

I honestly don't see the big deal about plastic tanks. I just replaced the radiator on my 93 Toyota P/U two years ago. It was aluminum with plastic tanks. It only lasted 10 years and 200,000 miles. I always hear plastic tanks or epoxied tanks as a criticism, but IMO 200,000 miles is a good bit of service for a radiator.

[sblake01]

I only mentioned the plastic tanks to say that when they develop a leak between the tank and the core, it means replacement rather than repair. 200,000 mi. is great service for a radiator. At 160,000 mi. I was able to get my Cu/Br radiator rodded out and re soldered for $60 and it works as good as new. Better maintainence by the PO might have made mine last longer.

[Mat M]

...snip...

Also to note, black is the best colour for transferring heat, silver is the worst.

Lastly, a 280zx radiator will easily fit into a 240Z, but the bottom tank will hang down by 4cm approx. ...snip....

I agree. the color black was termed the "perfect emitter" in PChem class.

I have a ZX radiator in my 240, It does fit, and it is a bit lower than the front valance. I am seriously contemplating adding oil lines to the extra interior core for the extra cooling. I just have to be vigilant about those parking blocks!

Would you want aluminum wiring in your house?

The reason the UBC went to Cu instead of Al was due to the fact that the Al alloy has a lower melting point than the Cu alloy, and would melt, then spark and create fires.

[EricB]

jmortensen you tore up 2 radiators just with chassis flex??? geez wow... that's crazy... I never would have suspected that was even possible...

Curtis240Z thanks for the arizonazcar website - I had forgot to check them and am impressed with their price - much lower than MSA... Good tip!

-e

[jmortensen]

Yep, autoxing with 250mm wide slicks. No cage was a problem I'm sure, had a triangulated strut tower brace for the 2nd one, but the first one didn't even get that. Spring rate was 200 in/lbs front, 250 in/lbs rear. They both just started weeping coolant near the corners of the top tank after a while. 1st one was old, 2nd was new. I did have the first one soldered, and I'm sure I could do the same on the 2nd, but I'm just going to get an aluminum one and soft mount it instead to save weight.

[EricB]

Impressive...

While we're on the topic I thought I'd ask you all something else, we discussed about how black is established as the best colour to get rid of heat, etc... How come I've never seen anyone take an Aluminum radiator and before first use have it anodized black??? What do you all think about that?

-e

[jmortensen]

Should work, but it's overkill. Why bother when the silver works good enough.

[EricB]

Just curious to throw that out there as food for thought, you know....

-e

[Mat M]

The flip side to having the "perfect emitter" is that it is also the "perfect absorber," as well. Having something reflective will reduce the amount of energy gained, but I would think it would be so vanishingly small that it wouldn't create an issue. Annodizing would negate this issue, but like Jmortensen said, it's overkill.