Copper Brass Radiators Versus Aluminum Radiators

Back in the day, if you needed a new radiator for your hot rod, your buddy probably said:

“Just get yourself a good 4-row”

Before aluminum radiators were around, the only upgrade from a factory 3-row radiator was either a 3-row high efficiency model or a 4-row. A 4-row added another row of cooling tubes which provided approximately an extra 20% of cooling power over a 3-row. Back 30 years ago, you could roll down to your corner radiator shop and even have him ‘recore’ your factory radiator with an upgraded 4-row core.

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However like many thing in life, not all 4-row radiators are made the same. Back in the day, there were snake oil radiator companies that made cheap 4-rows. One way they accomplished this was by using tall fin heights and smaller tubes. A good 4-row radiator would have 4-rows of ⅝” tubes where as a cheap model would have 4-rows of ⅜” tubes.

These snake oil companies took advantage of most people’s ignorance and sold them a cheap 4-row that wasn’t likely to cool any better than the 3-row they had. Infact, in many cases, it might even cool worse.

Fast forward from the 1970s to the 1980s. Fuel economy is now becoming important and car manufacturers are looking for ways to make lighter cars. Switch the radiator from a copper/brass to aluminum model can save 10-20 lbs in many cars. For us hot rodders, weight is bad. So ditching the copper brass radiator for an aluminum model is a no brainer.

There are many old wives tales about why aluminum radiators cool better. The most common one is ‘aluminum dissipates heat faster than copper’, which isn’t true at all. Copper is an excellent thermal conductor. In fact, copper has almost twice the thermal conductivity of aluminum.

Yet, despite having a much lower thermal conductivity, aluminum radiators can transfer a lot more heat away than their copper/brass counterparts. You many be wondering how in the world that can be? It’s a great question with a simple answer, which we will explain in our next e-mail. Watch your inbox for the next few days.