How long do Aluminum Exhaust Manifolds last in salt water. Also the same question for heads and intakes. Do brands make a big difference. I was told cast iron manifolds will live longer? I have a long history with outboards and have not seen many cast iron ones?
The help is appreciated.

Thanks For The Help,

Daddio

If you have a long history with outboards then you know that they are all alluminum. How long do they last There is a diference btwn outboards and IO's The water tends to stay in the manifolds and motor so a good flushing after each use is required. Also there are some products that you can coat the heads and intake water passages with. You have to check but manifolds like Stainless marine coat the inside of their manifolds.

Jon

Flushing is the key. I know a guy that ran aluminum heads in salt for seven years, took them off and resold them.

Outboards are designed to drain when you shut them off, so salt water doesn't sit in them like a I/O motor.
Cuda's right about the flushing.

although flushing is key, a friend of mine flushes after every use, boats in Barnegat Bay, and cant get more than 2-3 seasons out of a set of heads.

I've heard the small cruiser guys (who don't flush) running gas in salt plan on new exhaust elbows every season, and entire manifolds every two.

We flush with soapy water after every run and the aluminum parts look good after 3 seasons-brackish water.

can you elaborate on flushing with soapy water ?

I do the same thing. I'll squirt some liquid dish soap into the hose before flushing, then hook it up. I don't know if it helps or not, but it makes me feel better.

I can also tell when the motor is completely flushed when the suds quit coming out.

Has anyone tried anodize or some other coating? I see that the edelbrock alum heads come with a anodize coating to help with the harsh environment. Sounds good but how effective???