I need to replace the copper/brass replacement radiator on my 65 and have just about talked myself into going back to aluminum($$$) but the recent thread about C3's has peaked my curiousity. Why were copper/brass units used in A/C and AT (options requiring better cooling) cars from this period?
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Re: Aluminum vs. Copper/Brass Radiators
Dunno what the logic was on those C3's, but you DON'T want another copper/brass replacement radiator; the "cure" is to restore the original designed-in cooling capacity (and margin) with a reproduction Harrison stacked-plate aluminum radiator, which has about 30% more cooling capacity than the C/B replacements, so you can watch the scenery instead of the temperature gauge. -
Re: Aluminum vs. Copper/Brass Radiators
Scott-----
The C3 copper brass radiators were of a TOTALLY different configuration than the C2 and C3 aluminum radiators. Basically, the C3 copper brass radiators were of the same GENERAL size and configuration as the 1966-67 big block radiators. They were MUCH larger than the 63-72 small block aluminum radiator.
A copper brass REPLACEMENT for the 63-72 aluminum radiator WILL NOT perform as well as the aluminum radiator. Period.In Appreciation of John HinckleyComment
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Geometry issue
Whip out your Handbook of Chemistry & Physics and compare either the thermal conductivity or electrical conductivity (they march together) of copper/brass to aluminum. It's a BIG advantage for copper/brass vs. aluminum. So, why are aluminum radiators so popular?
Well, cooling is a matter of heat transfer and transfer rates (BTU's and BTU/time). You maximize heat transfer by making the cooling tubes as THIN as possible and hitting maximum packing density on the cooling fins. You reach a point with copper/brass where the geometry you're trying to hold passes the metal's strength (rigidity and ability to hold pressure).
Aluminum being stronger can achieve increased packing density and therefore, in an 'apples to apples' situation (BTU per cubic inch of radiator) surpass copper/brass construction. It's also lighter. So, you'll find high performance race cars almost exclusively running custom aluminum radiators.
In Corvette, when the radiator changes from aluminum to brass, the core support size jumps along with the total X-section of the radiator. My hunch is designers hit the limits of thermal dissipation with their aluminum radiator (adding automatic trans cooling, AC feature, Etc.) and had to scale the rad size up. Once this size bullet was bitten, I venture copper/brass was used for economic reasons.
You'll note the MONSTER Corvettes that ran aluminum radiators (396, L88, Etc.) were also LIMITED in terms of their option list (typically no automatic trans, no A/c, Etc. when combining big HP under the hood with the aluminum radiator).Comment
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Re: Aluminum vs. Copper/Brass Radiators
Scott - Take John's (and other's) advice seriously. I battled an over-heating problem on my '67 SB. With a CU rad, it ran too hot, and under certain circumstances, forced me to shut it down. The board's advice...?
**** Get an AL from DeWitts. Don't think about it. Just do it. I've been there; hadda do that...and I'm glad.
TomComment
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Re: Aluminum vs. Copper/Brass Radiators
I'm convinced...I'll take aluminum! Corvette Central lists the unpainted, non-date coded DeWitts for $649 (Item# 242141). Any comments on buying from them rather than directly from DeWitts ($695)?Comment
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Re: Aluminum vs. Copper/Brass Radiators
In your shoes I would call Tom DeWitt and ask him if he will match the CC price. Who knows, maybe he will even offer to beat it.Comment
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Re: Aluminum vs. Copper/Brass Radiators
You might want to contact Ernie at Willcox@Bellsouth.net.
MikeComment
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