I will be building a new short block after this summer. I'm considering buying either brodix or dart pro1 hard anodized heads & running them this summer. I will install a battery switch & probably add closed cooling when I put the new short block in.

personally I would not run aluminum heads without closed cooling...just asking for issues...as you see...and with all the crap aluminum being used it's a crap shoot at best !

My whole family has ties to the University of Alabama School of Metallurgical Engineering...the Metal Castings Lab was named after my Grandfather.

We all talk about this stuff alot because we all like to boat and we are all gear heads. Simply put...you have ferrous (Iron Block) and non ferrous (Aluminum Cylinder Heads) connected to each other via the HEAD BOLTS sitting in an electrolyte (Salt Water) creating the perfect scenario for galvanic flow. The only way you prevent this from happening is to isolate the 2: dis similar metals (no such thing as Aluminum Head Bolts) or remove the catalyst to the reaction...the electrolyte or Salt Water.

The quick fix: Closed cooling with corrosion inhibitors (antifreeze)in the coolant. Anything else is waving a balloon in the air so to speak. Marine Aluminum intake manifolds hold up quite a bit better because the water passages are lined with brass.

Hard anodizing can slow it down but it's not an if but a when.

If Aluminum heads are worth the effort...bite the bullet and change to closed cooling...everything will last longer.

So what happens if you say, boat 100 % in fresh water and the alum heads and iron block never see salt water just fresh lake water, should there be any concern of the heads corroding in that environment?

thanks for the reply!! yes closed cooling in in the works.

If it is clean fresh water you will be ok. Lots of 15+ year old AL heads in my lake with no problem at all.

I have aluminum heads on my boat, they were hard anodized and after 3 years in fesh water they had some pitting in the areas around the holes where the gaskets have slightly bigger holes and trap water, I can't imagine how to get them to live in salt water, Smitty
I see mention of getting used heads re-annodized after repair, where can you send used heads? Smitty

My anodized AFR heads from RMBuilder look like they first anodized the casting, then machined the heads. I don't know how you would anodize used heads.

Mine too and where the water port holes align with block the holes and the surfaced aluminum hole is smaller than hole in gasket they started pitting and rotting enough where I had to have a considerable amount taken off heads to clean them up but obviously the head surface has to be machined after they are hard coated, Smitty

If AFR would drill and tap the water ports, they could screw in bronze inserts and stop the corrosion from head gasket holding water.