Do I need to replace my exhaust elbows?

[Jodahl]

Hi,
As my boat celebrate 10 years this year, all of them operated i salt water, I decided to have a look at my exhaust manifolds and elbows. I have a closed cooling system and the motor, 4.3 MPI, has about 200 operating hours.
As you can see on pictures (I hope the link is working) the gasket between manifold and elbow is closed, so there is salt water in the elbow and closed cooling water in the manifolds. I was a bit surprised to see this as it is not how it is described in the service manual.
The elbows look quite good compared to pictures I have seen of other elbows, so I hope I can operate them for some more years. Anyone here with experience agree?
I didn't bother to dismantle the manifolds as they seem to be in good condition, and are not exposed to salt water.
I have never experienced high temperatures, the motor is running well below 180F.

https://imgur.com/a/rreuB

Regards,
Johan

 

[scoflaw]

None of those pics show the area where those dry joint elbows fail. Elbows rot through in the reversion break area, a recessed area that holds a bit of water . Visible, by looking into the exhaust discharge end. Problem being you can't tell how much metal is left before it breaks through

 

[Lou C]

10 years, change em!
​why take a chance of ruining a nice closed cooled engine by letting 10 year old risers leak salt water right in the center of your center riser manifolds!
​With raw water cooled exhaust I never went past 6 years on them and I never had water in a cyl from the exhaust. Think of it this way, you're way ahead of the game cost wise because you don't have to do the manifolds. Just make sure to carefully clean up the sealing surfaces, and put paper towels in the center exhaust port to keep debris from running down in the cyls exhaust ports. Then use a shop vac to vaccum out any old gasket material, sanding debris etc.

​I could show you a pic of my last set of OMC batwings that look great on the outside, but had flaking rust in the exhaust riser end and when tapped with small hammer, this would drop down into the engine exhaust ports.
​If you want to never have salt water in your engine from exhaust, then change every 5/6 years. Use Barr aftermarket they are cast in USA and good quality.

 

[Jodahl]

Thanks, if there is no way to visually see if they have to be changed I guess from what you are writing, I will have them changed.

Should I have a closer look at the manifolds as well? They had coolant fluid in them so I haven't really been able to look into them.

I live in Sweden so I'm not sure a can get hold of Barr. I've seen aftermarket elbows and risers made from aluminum, is this a good option?
I don't know what you pay in the US but here, an elbow is about 500 USD and manifold 600 USD.

 

[Lou C]

You should not have to replace the exhaust manifolds if they are on the closed cooling side as long as you can get the sealing surface well cleaned up and flat and level to less than .002".
​This is the Merc Dry joint system so you can use Merc OE, Barr, Osco, those are the best brands based on feedback here in the US. GLM I would not take a chance on, unless they have really improved their quality control. The best way to know is to carefully use a straight edge and feeler gauges to check how flat & level the machined sealing surfaces are. That and use OE Merc gaskets.

 

[achris]

From what we can see, for 10 years those elbows look great. As already said, closed cooled manifolds should last the life of the engine.

Chris........