Sacrificial Anode

[jhaag]

This is an interesting, thought provoking thread. Having said that, why so much angst on the subject? Car manufacturers have been mixing and matching aluminum heads and iron blocks for decades. If it works for them, why not us? The last motor I built using aluminum heads and radiator, I ran modern coolant, dexcool I think, and never had a problem. I am not against using a sacrificial anode, but have to wonder if it is really needed?

[cudabob496]

This is an interesting, thought provoking thread. Having said that, why so much angst on the subject? Car manufacturers have been mixing and matching aluminum heads and iron blocks for decades. If it works for them, why not us? The last motor I built using aluminum heads and radiator, I ran modern coolant, dexcool I think, and never had a problem. I am not against using a sacrificial anode, but have to wonder if it is really needed?

I don't think there is "so much angst"  Just some concern on my part. And regarding car manufacturers, when did they ever built an engine to last as long as possible? Their goal is usually to make as much profit as possible, so they will always cut corners, as long as they can come close to meeting their warranties. With the economy as bad as it is, any cheap insurance is probably worth it, compared to an engine overhaul.

[EB3-GranCoupe]

 

It certainly won't hurt to have it installed.

I went to my local parts store to ask if they had one, which they did not. but, they suggested this product:
http://royalpurpleconsumer.com/products/purple-ice-radiator-coolant-additive/

Obviously not a replacement for an anode, but the cooling properties are intriguing.

[cudabob496]

Well, I put this in my water pump housing today, so we'll see how it goes.
I cut off about 3/4 of an inch of it, as I did not want it to interfere too much with
coolant flow.  Also, I'm concerned about the zinc portion falling out, as it screws into
the brass housing. May have to check it periodically.

http://www.summitracing.com/parts/flx-32060/overview/

[KiwiChallenger]

This is and interesting topic but you may be over thinking it a little. Electrolysis or galvanic corrosion is caused by current passing from one metal to a dissimilar metal through a liquid.
I am an Auto Electrician and I do some work on aluminium boats. To prevent corrosion on these we keep everything above ground, that is everything is earthed to a battery or insulated earth point.
It is the same theory in a car, if you have an aluminium radiator do not earth anything to it and ideally rubber mount it. Make sure the earth lead to the engine is bolted to the block and not to an aluminium head or water pump housing, and if possible put a heavy earth lead from the alternator to the battery.
Electrolysis is a potential problem but if you do this you should not have stray current in your cooling system and you should be safe.

Monitor your anode if it is pitting or shrinking you have stray current or and earth problem that needs to be fixed.

[cudabob496]

This is and interesting topic but you may be over thinking it a little. Electrolysis or galvanic corrosion is caused by current passing from one metal to a dissimilar metal through a liquid.
I am an Auto Electrician and I do some work on aluminium boats. To prevent corrosion on these we keep everything above ground, that is everything is earthed to a battery or insulated earth point.
It is the same theory in a car, if you have an aluminium radiator do not earth anything to it and ideally rubber mount it. Make sure the earth lead to the engine is bolted to the block and not to an aluminium head or water pump housing, and if possible put a heavy earth lead from the alternator to the battery.
Electrolysis is a potential problem but if you do this you should not have stray current in your cooling system and you should be safe.

Monitor your anode if it is pitting or shrinking you have stray current or and earth problem that needs to be fixed.

You make some good points. I do have engine grounds coming off my aluminum heads to the firewall.
Regarding the radiator, why could not current run from the radiator, through the coolant, to the iron block, to ground, thus
creating the potential for aluminum radiator corrosion?

[KiwiChallenger]

The engine is earthed to the battery, the body is earthed to the battery, the radiator is earthed to the body but not the engine. The only time current could flow from the rad to the engine through the coolant would be if the engine had a bad earth to the battery.
In the 14 years i have been working on cars i have only seen 1 instance where electrolysis killed a radiator and it was on a cop car that some idiot had earthed the siren to the radiator.

[cudabob496]

The engine is earthed to the battery, the body is earthed to the battery, the radiator is earthed to the body but not the engine. The only time current could flow from the rad to the engine through the coolant would be if the engine had a bad earth to the battery.
In the 14 years i have been working on cars i have only seen 1 instance where electrolysis killed a radiator and it was on a cop car that some idiot had earthed the siren to the radiator.

OK, but I'm still a little concerned about the aluminum heads and water pump. That's why I think the $20 zinc sacrificial anode may be some cheap
insurance.  Maybe if we do all the electrical wiring perfectly, then corrosion on the heads and water pump might not be a concern.  But so far, I've never
done anything perfectly on my Cuda.  There's always something that can go wrong, or that I didn't do quite right.

[cudabob496]

It certainly won't hurt to have it installed.

I went to my local parts store to ask if they had one, which they did not. but, they suggested this product:
http://royalpurpleconsumer.com/products/purple-ice-radiator-coolant-additive/

Obviously not a replacement for an anode, but the cooling properties are intriguing.

Ya, that's good stuff. I put in a bottle!

[EB3-GranCoupe]

Ya, that's good stuff. I put in a bottle

I went ahead and bought some.  I run hot, so i am curious to see if that will make it run any cooler.

[cudabob496]

I went ahead and bought some.  I run hot, so i am curious to see if that will make it run any cooler.

My July Hot Rod Magazine had a good article on diagnosing an overheating problem.

[EB3-GranCoupe]

Thanks, I'll have to check it out. i'm sure timing is part of the equation, and 440's are supposedly warm-blooded to begin with.  I probably worry more than i should, but i would like to see the needle a little lower on the guage!