Originally Posted by Deejay
Originally Posted by Rog
Originally Posted by Deejay
Be good to have a report back when done

No problem Doug.

Don't think it will be an issue. It’s the same shape/profile as the other spouts the hose connects to on the car - thermostat, header tank, head outlet manifold etc.
Interesting concept this, which I think few people would have considered.

FWIW, I measured voltage between the top of my sifab aluminium radiator and the OEM stainless pipe that runs across the top of, and parallel to, the camcover. I got 0.44 Volts!
I don’t know much about the detailed science of galvanic corrosion, but googling around, it would appear that 0.25 volts is seen as a critical figure.
However, in one article from “Allied Corrosion Industries” it listed the 4 requirements for galvanic corrosion to occur.
It stated that you need:
Anode
Cathode
Both to be immersed in the same electrolyte
There must be a return path for electronic current flow, also known as the “metallic path”

So from that, the fact that we have rubber pipes between anode and cathode, in the absence of the metallic path, is it really a problem?
Any contributions from experts welcomed.

My ali rad and top pipe shows about 0.3v. That will decay too, particularly if shorted. So I guess there is some chemistry happening. Probably dependent on the electrolyte/coolant condition too.

Would also be very interested to find out if some clever person knows for sure. I don’t know how the physics plays out with respect to the system level ‘galvanics’. It’s complicated so am airing on the safe side with my new ali T connection.

One thing I do concur with is the 0.25v safeish figure from a galvanic design perspective regarding material selection. It’s always something that needs consideration and very dependent on the operating environment, that’s basically where I’m coming from.

It’s only anecdotal but on my first ali engined Duratec car, I lost two copper/brass cores in a relatively short succession before I changed to an ali rad (I think that CU/brass rad arrangement may have had an earth path). On both occasions the cores sprung multiple powdery pinhole leaks so have been super cautious ever since.

Roger
2011 Plus 4