Exhaust Bends and Cast Iron vs. stainless Steel

[CharmCityBoater]

Members,

I am trying to find a replacement exhaust bend for my Yanmar 4JH4E engine. The OEM part is made from cast iron and not stainless steel. I had a few people tell me that the part "HAS" to be made of cast iron, not stainless. With that said I cannot find a replacement part for it in cast iron. HDI marine makes one in stainless steel. but was told it has to be cast iron.

This is not the wet exhaust mixing "elbow", Yanmar refers to it as a "Bend". This is the part that bolts to the exhaust manifold prior to the water mixing. I think the exhaust manifold is made of aluminum and that is why the say do not use stainless steel? dissimilar metal corrosion?

Can anyone shed light on this subject or provide me a link to the actual cast iron part that is in stock somewhere?

Here is the HDI listing: https://hdimarine.net/product/jhl-st...-exhaust-bend/

Thanks

Phil

[SOLAR SUPPORT]

Don't listem to them. SS elbow is much better than the cast iron made. Yanmar do the right thing. Just make sure you have the siphone system which empty sea water coolant in the heat exchanger in to the muffler when the engine stops. I changed my ironcast VP elbow 5 years ago with the SS 316L modified. It is still in good condition.

[s/v Jedi]

Originally Posted by CharmCityBoater

Members,

I am trying to find a replacement exhaust bend for my Yanmar 4JH4E engine. The OEM part is made from cast iron and not stainless steel. I had a few people tell me that the part "HAS" to be made of cast iron, not stainless. With that said I cannot find a replacement part for it in cast iron. HDI marine makes one in stainless steel. but was told it has to be cast iron.

This is not the wet exhaust mixing "elbow", Yanmar refers to it as a "Bend". This is the part that bolts to the exhaust manifold prior to the water mixing. I think the exhaust manifold is made of aluminum and that is why the say do not use stainless steel? dissimilar metal corrosion?

Can anyone shed light on this subject or provide me a link to the actual cast iron part that is in stock somewhere?

Here is the HDI listing: https://hdimarine.net/product/jhl-st...-exhaust-bend/

Thanks

Phil

I have an HDI elbow on my Yanmar 4LH-HTE and am very happy with it

[nuku34]

should be pretty easy to find out if your exhaust manifold is alloy; I doubt it. In any case, put some sort of anti-corrosion goo on the threads of the SS bolts that hold the SS exhaust bend to the manifold, and you shouldn't have any problems

[SOLAR SUPPORT]

The exhaust manifold is aluminum or not, you have to put a gasket between it and the exhaust elbow. This gasket is sufficient to prevent gas leaks. It also prevents the formation of imaginary electrolysis 🙂.

What finishes the Exhaust Manifold is the rusting of the exhaust elbow, which is shorter than it should be and made of iron casting, in a short time.

Flow irregularities and blockages caused by the oxidation of the elbow and disrupting the gas and liquid flows cause problems starting from the engine manifold to filling the crankcase with coolant.

[Galumay]

The HDI stainless exhaust manifolds are fantastic, you wont go wrong with them.