I have installed a sacrificial zinc anode in my aluminum radiator to protect the aluminum radiator, intake and cylinder heads from the effects of dissimilar metals. I have never owned a classic car with aluminum engine components so the $5 zinc anode seemed like good insurance against electrolysis in the cooling system. The car has a freshly built small block with no drive time yet, just idle time in the driveway and pulling into and out of the garage.

Today I pulled the thermostat housing to replace it because it has a small pin-hole leak in the side from previous corrosion issues. I was surprised to find that the zinc anode in the radiator already has significant scale on it with only a few hours of run time. Is this scale an indication of electrolysis in the cooling system? Is the zinc anode not a good idea? I'm using Zerex red coolant as spec'd for Asian cars (Toyota, Nissan, etc.) This coolant seemed like a good choice based on the corrosion additives and lubricants and should be good protection for the aluminum parts. Here's a few pics:


The brass plug in the radiator is the sacrificial zinc anode.


Here is a pic of the scale on the zinc rod.

 

Nobody has any advice on this??

 

Maybe it’s a race thing like everything else these days and you sided with the wrong one. Japanese coolant?!? Just kiddin.

It seems to me that you’re on a reasonable track but I don’t know enough about it. My main experience with anodes is changing them in my water heater every 2-3 years, they come out uuugly. What I see with yours doesn’t seem to be unreasonable despite the short time. I wonder if it wouldn’t make sense to buy another one or two and see how quickly they deteriorate compared to this one. My only real question is why OE’s didn’t use them, was it lack of need, ineffectiveness or accountants?

I have seen numerous discussions regarding electrolysis, voltage charged coolant and grounding but like a tire, oil, or Olds cylinder head there are as many contradictions and disagreements as there are contributors.

We’re gonna need much smarter people than me for info on this.

 

Well its like everything else theses days, they don't want things to last, cant make money that way.

 

My wife's car has aluminum and iron components, in 15 years it has covered 250+k miles with just the recommended antifreeze mixed 50% with (hard) tap water. The aluminum radiator was replaced around 210k miles becaus it developed a leak, the water pump at 220k, nothing wrong with it, just because my wife bought it with a replacement cam belt.
So I don't think you will see any benefit from adding an anode to the system.
But if it makes you feel better about the car, then it certainly won't do any harm.

Roger.

 

Hi,

Sorry, I am not much of a help here, this is the first time I am seeing this. Cool idea. I too bought a new aluminum radiator, waiting for the car to arrive after the body restoration. Would like to see what others have to say.

Cheers!

 

I grew up in Minnesota, with the cold winters. Unless we used 50% antifreeze in our cars, the blocks would break in cold weather. So no one used water.

Our high-performance W30s and W31s had aluminum intake manifolds.

Until I moved to LA I had never seen an Olds aluminum intake with any corrosion. In LA (and here in Texas) those intakes that were pristine in Minnesota were badly corroded by water without antifreeze.

That's a long way of saying that if you use a quality antifreeze, you will have no corrosion problems.

But I think your anode is cool!