Exhaust Manifolds

[Thomv]

Looks like sooner than I expected, I will be replacing both motors exhaust manifolds and risers. Can someone chime in the pros and cons of going with aluminum manifolds vs the cast iron manifolds. I am seeing aluminum ones on line for about $250 a side.

 

[tpenfield]

Aluminum would be for fresh water only . . . Iron would be for salt water or fresh.

 

[Thomv]

Aluminum would be for fresh water only . . . Iron would be for salt water or fresh.

If the aluminum manifolds were flushed every time they were used in salt water would they still be as reliable as the cast iron units?

 

[tpenfield]

If the aluminum manifolds were flushed every time they were used in salt water would they still be as reliable as the cast iron units?

I have no idea, best to consult the detailed product literature.

 

[HT32BSX115]

If the aluminum manifolds were flushed every time they were used in salt water would they still be as reliable as the cast iron units?

They might be just as "reliable", but they probably wouldn't last as long as cast iron because they would corrode quicker in salt even if you did "flush" them.

Aluminum is "better" because it's lighter. They'll last a long time in closed cooled systems as will cast iron.

 

[TyeeMan]

Thomv,

I to need to do manifolds and might as well do risers. Can I ask where it is you found the aluminum manifolds/risers?

Also, as far as manifolds go in general do know (or does anybody know) what a good aftermarket manifold is, or which ones I should stay away from. I'm pretty sure the Volov manifolds are going to be pricy.

Thanks

 

[Thomv]

Thomv,

I to need to do manifolds and might as well do risers. Can I ask where it is you found the aluminum manifolds/risers?

Also, as far as manifolds go in general do know (or does anybody know) what a good aftermarket manifold is, or which ones I should stay away from. I'm pretty sure the Volov manifolds are going to be pricy.

Thanks

Two brands that come to mind are Osco and Bar. I believe both can be had in aluminum. I had a 24 foot baja sport that I bought used that had stainless Marine exhaust and stainless steel risers. Never had a problem and the boat was run in salt water only. I was very anal and always flushed after use. One one of my motors I ended up going after market and I had to modify for it to fit.

 

[bruceb58]

Even if you have closed cooling systems, the riser gets exposed to salt water. Personally, I only use OEM manifolds.

 

[midcarolina]

IMO this is one of those topics that is best answered by the manufacturers..........cause what you get in a forum is mostly opinion.

I can tell you a quick google search revealed several PDF files from munufacturers that say they work well in salt water, And have decent warranties, but just like cast iron flushing after use is a must do.

You kinda got to ask yourself why is there so many other items in boating made from aluminum..........The truth is salt water is hard on everything! and proper preventive maintenance is required to enjoy the expected life span of anything dealing with salt water.