Was discussing this the other week with Gav. What with the combination of copper pipe joiners and tees and an alloy header tank and rad. Will there not be some kind of corrosion risk presumably to the aluminium due to dissimilar metal corrosion? Hmmm

yes there will but should you be worried?

rover v8 is alloy block and was used with copper cored radiator; I am not aware that this caused a problem.
I am sure trhere any many more examples e.g. crossflow: cast iron block, aluminium alloy manifold, copper cored radiator so again, any one know of probkems casued due to this metal combination?

I am not worried.

Just wondered more than anything else. I am aware that there is some kind of corrosion inhibitor in the anti freeze too which would affect things.

what you are refering to is electolitic corosion and as far as i am aware this is only present when you have water on its own without antifreeze is quite a common problem in plumbing and is overcome by using gun metal fittings i can only assume the automotive world uses a better grade of metal.

i assumed electrolytic corrosion only happened between two metals in contact.
as in the aluminium has to be in contact with the copper, so if the 2 are joined by a pipe full of water, nothing will happen. the corrosion inhibitor is to stop the coolant eating the inside of the block/head

more commonly, stainless steel can be isolated from aluminium when riveting by dipping the rivets in sealer to stop the corrosion. if it wasn't the stainless would soon rot the rivets.

clear as mud i know...
tom

This gives quite a good explanation
http://en.wikipedia.org/wiki/Galvanic_corrosion.

Just use a 55% solution quality antifreeze all year round.

If the system has been cleaned out completly use an longlife OAT coolant but keep in mind you can't mix it with the conventional blue/green antifreezes.

Electrolytic corrosion can only happen in a relatively dry joint between dissimilar metals - I think we are talking about a cooling system filled with water that will dissipate any electrical charge so it wouldn't apply.