Coating a new exhaust elbow inside to slow corrosion?

[vyv_cox]

Is there any reason why many exhaust elbows are complex, dual walled (thus expensive) affairs whereas Beta elbows are just a bent pipe with an injection point?

Simply a simpler, cheaper solution I guess. Do they last well?

There might be a greater tendency for water to enter the engine without the inner tube. Is this a problem?

 

[alahol2]

I think the Beta elbows are cast aluminium. My first replacement was at about 1200hrs /10 years but on lightly used 13hp. I've never heard of any water ingress problems. It just seems that there is an opportunity to make/market a much simpler/cheaper design for other engines...

 

[Refueler]

Is there any reason why many exhaust elbows are complex, dual walled (thus expensive) affairs whereas Beta elbows are just a bent pipe with an injection point?

My VP is Cast Iron !! not steel .... so that adds another dimension.

 

[Dockhead]

Mine is bent thick-walled stainless pipe, made up by the engineering shop in Cowes. Going strong after a few thousand hours.

 

[marcuc]

Is there any reason why many exhaust elbows are complex, dual walled (thus expensive) affairs whereas Beta elbows are just a bent pipe with an injection point?

Yes and interesting to see the drawing on a previous post of a bolt together diy made from available plumbing bits that was made for a yanmar that is exactly that with the water into the last bit of single pipe