2005 5.0 MPI Manifold and Risers (Dry Joint)

[OllieC]

Well I just received the latest issue of Boating Magazine. In the Mag, it discusses Manifolds and when a good time to replace them would be.......which freaked me out.

I have a Dry Joint with a Standard cooling system. In boating, it says if your boat lives in salt water you "may" get 5 years and if in fresh you "may" get 10 years on them.

The boat is trailered and has 380hrs on it. I purchased the boat from my dad about 3 years ago which was used in salt. My dad always flushed the motor however he never put any coating on the block when it was sitting at the marina in S. CA.

Now I have it and it has only been in fresh water. The engine performs flawlessly IMO and I am always up on the maintenance.

Here's a pic of my starboard manifold and riser. There is some surface rust, but I see no leaks....should I be concerned?

(this pic was taken when I just got the boat - I've cleaned the bilge and motor up since :redface-new: - the surface rust hasn't increased)

 

[Bondo]

Re: 2005 5.0 MPI Manifold and Risers (Dry Joint)

Ayuh,.... With the visible seepage at the bottom of the riser block,...

I'd pull 'em apart, 'n have a look,....

If they're Ok, get new gaskets, 'n put 'em back together,...

'n as far as that article goes,... 'round here on the sweetwater seas, manifolds, 'n riser last til they're left fulla water in winter, at which point they freeze, 'n crack....
Rust is a Non-issue,...

 

[OllieC]

Re: 2005 5.0 MPI Manifold and Risers (Dry Joint)

Thanks Bondo

 

[achris]

Re: 2005 5.0 MPI Manifold and Risers (Dry Joint)

My raw-water cooled 2006 engine is saltwater only, and I flush 95% of the time within a few minutes of coming out of the water (also no snake-oil coating). Still running original (dry-joint) manifolds and elbows.

Chris.....

 

[OllieC]

Re: 2005 5.0 MPI Manifold and Risers (Dry Joint)

Lets say this Spring, if it ever comes to MN, I decide to "just" replace the risers, gaskets and clean up the manifold - should I stick with Mercruiser OEM or will an off brand be ok?

 

[Scott Danforth]

Re: 2005 5.0 MPI Manifold and Risers (Dry Joint)

for the gaskets, go OEM. stay away from the Sierra green gaskets.

for manifolds and risers, you can go OEM, or get Osco or Barr (both supply castings to the OEM)

Or if you want to save weight and are in fresh water, switch to alumium. My next manifolds will probably be EMI's with a stainless riser.

 

[OllieC]

Re: 2005 5.0 MPI Manifold and Risers (Dry Joint)

for the gaskets, go OEM. stay away from the Sierra green gaskets.

for manifolds and risers, you can go OEM, or get Osco or Barr (both supply castings to the OEM)

Or if you want to save weight and are in fresh water, switch to alumium. My next manifolds will probably be EMI's with a stainless riser.

If I went Aluminum on Steel manifolds, could that cause a corrosion issue with dissimilar metals?

 

[achris]

Re: 2005 5.0 MPI Manifold and Risers (Dry Joint)

If I went Aluminum on Steel manifolds, could that cause a corrosion issue with dissimilar metals?

Not in freshwater, it's not a good enough electrolyte to cause any significant problems.