can you use aluminum in a salt water inviroment

[wrench001]

morning all. working on my winter project of building a new engine for my boat. can i use aluminum intake manifold on my 360 merc (gm5.7) with out any i'll effects like rotting or electrolosis. i have a edelbrock carb and want to match the intake. the boat does stay in a slip for 6 months a year. I was probably gonna paint it. anyone have any advise. thanks in advance.. steve

[Don S]

It's not recommended if using a raw water cooling system. But if you have a closed cooling system, it will work fine.

[LEADLAP]

It will also be FINE in raw water cooled system if you use a couble of pencil zincs in any of the water plugs not being used for temp sensors/sending units. The zincs won't stop all of the corrosion, and the life expectancy in raw water will be less than with fresh, but they will help.

I yank mine at the end of each season to clean out the water passages and check the sealing surfaces.

Don't paint the intake. Simply clear-coat it to prevent oxidation on the exterior..

[wrench001]

thanks guys. hmmm clear coat. freaking awesome idea!!

[Don S]

Not knowing the alloy of the aluminum the manifold is made of, sticking a zinc in it as suggested may cause it to go away faster in a salt water cooled system with a zinc than without one.
That is why they are not recommended in raw water systems. Even Mercruiser and Volvo on the newer engines with alum manifolds have a brass insert in the water passage of the manifold.

[f_inscreenname]

I use a Edelbrock Air gap intake. It only has one passage for water, from to thermostat area into the block. The rest of the water cross overs are closed off. 6 years and no issues. Now I also tried to use a aluminum timing chain cover (with a mopar small block water runs through it also). Less then one season and a hole corroded in it filling my motor up to the top with bay water in about 100 yards when it happened. Not good.