I'm kind of laid up for the holiday weekend, and my mind keeps jumping all around on the future of various projects. The one thing I keep returning to is when building the cooling system for a street car, running regular 50/50 antifreeze/h2o, and maybe eventually a water wetter, can I use brass soldered plumbing tubing? Aluminum? Stainless? Steel?
Let's assume a cast iron block, aluminum head, figuring this would also be good for aluminum block/head applications. My specific question is about cavitation, specifically, the kind that ruins heads and such.
Which metals are incompatible in this application?
Would more thorough grounding alleviate this situation? Thanks in advance to the brain trust with this little exercise.
Do you mean galvanic action? Isn't cavitation something unrelated to metal composition?
In terms of corrosion I thing the antifreeze, at the right mix and freshness, is intended to be compatible with multiple metals in the same application. Aluminum and steel are pretty far apart on the galvanic table so if they are able to run standard 50/50 mixes and not disintegrate I don't thing introducing some brass is going to change that. IIRC a lot of 80's model cars had brass in the radiator assembly standard.
wheelsmithy wrote:
I'm kind of laid up for the holiday weekend, and my mind keeps jumping all around on the future of various projects. The one thing I keep returning to is when building the cooling system for a street car, running regular 50/50 antifreeze/h2o, and maybe eventually a water wetter, can I use brass soldered plumbing tubing? Aluminum? Stainless? Steel?
Yep, yep, yep, and yep. Those have all been used on OE vehicles.
You can also use plastic (not PVC or black pipe obviously) and rubber too!
I know Alfa (or the aftermarket) did this. They had zinc anodes that you could replace in the cooling system. The theory was that the coolant would carry a charge between the aluminum head, iron block, and brass radiator.. and the zinc would be the first to suffer
Thanks, guys. I just had a paranoid jag that the aluminum head would be eaten away. I know a lot of heater cores are brass, a well as radiators, but just wanted some reassurance. Neat-o
Anti-corrosives have come a long way since that was a problem.
One thing I was reading said people used to use saltwater to prevent freezing... !!!
Most important thing to do concerning aftermarket radiators(or heater cores I guess) is to make sure the radiator is NOT grounded. It needs to be isolated from chassis ground or else it provides a current path for electrolysis to happen.
There was a Ford TSB years back because techs were grounding the heater cores in an attempt to help the issue, and it made it worse.
Disconnect the battery, use a DVOM set to voltage(checking both AC AND DC), touch the negative lead to the negative terminal(of the harness, not the battery itself), and dip the positive lead into the radiator coolant. IIRC voltage above 0.4v was considered problematic and required flushing the coolant.
Then you reconnected the battery and retested the same way while engine is running, if voltage increased you disconnected the alternator to see if the voltage dropped again to indicate bad diodes inside.
In a nut shell isolate the radiator with rubber mounts, keep your engine and chassis grounds very clean, and drain/refill coolant often.
