Has anyone had experience with aluminum exhaust manifolds on mercruiser engines? How's the corrosion?

Question

I need to replace my exhaust and the manifolds I am looking at are aluminum with zinc anodes. I was wondering how good this will hold up.

Answer 1

Are you in fresh or salt water? Maybe ok in fresh but in salt water it will be a big headache for you. Not only will you have to worry about electrolysis but even the exhaust gases will create acids that will eventually destroy the manifold. besides cast iron how about stainless? Very expensive though.

Answer 2

I would think it would be great and work well, Sounds costly though. being that they are aluminum though, I wonder why they would put the zincs in them?