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Replacement Exhaust Elbow


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#1 Frank

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Posted 14 August 2019 - 12:12 PM

Hi All, any guidance appreciated !

 

So the cast iron exhaust elbow on my Volvo MD7B has rusted out, no surprises there as they only last about four seasons. I have been quoted $800 for a replacement so I am looking at fabricating something in Stainless Steel. I would appreciate any input from someone who has done this, for instance what grade of Stainless would you recommend ?

 

I have sliced it in half to show the inner geometry, my thoughts were to use to fabricate the unit using cast butt weld elbows from the Anzor catalogue with some suitable straight pipe in the middle. From there I would weld a smaller dia pipe in top to inject the cooling water.

 

Thoughts ?

 

chrs

 

Frank

 

Attached File  20190814_050320.jpg   1013.7KB   1 downloads

 

 


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#2 Island Time

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Posted 14 August 2019 - 12:15 PM

Like this? https://www.boatsand...stainless-/1563

Stainless often has similar life to cast iron. It does not like hot salt water....

 

Or this?

https://www.frenchma...t-Elbow-921-172


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#3 wheels

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Posted 14 August 2019 - 12:21 PM

316 is best as it has the greatest resistance to Chloride (Salt) and yes, the cast is best as 316 is prone to cracking from vibration and heating/cooling. So a decent wall thickness is needed, good welds and decent thickness for flanges.  I have used SST for the same use and it has lasted several years.


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#4 Frank

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Posted 14 August 2019 - 04:01 PM

Thanks Guys and good spotting Matt ! The UK SS version seems like a good fit, I will make enquiries.


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#5 Frank

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Posted 16 August 2019 - 04:45 AM

Attached File  20190816_042215.jpg   1.3MB   4 downloadsGame on


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#6 lateral

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Posted 16 August 2019 - 12:29 PM

Keep pic's coming!


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#7 Frank

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Posted 18 August 2019 - 03:06 PM

It will be welded by Mon, the bits cost $80 at ANZOR, I will post another Pic.


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#8 Cazzate

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Posted 18 August 2019 - 03:10 PM

Nice Scottish Jandals mate !
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#9 Frank

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Posted 20 August 2019 - 04:50 PM

The Jandals are a special type for welding, here it is all welded up, Im experimenting with injecting the hot seawater down stream from the exhaust elbow. The specs of the exhaust hose say it is good up to 100 deg c so we shall see.

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#10 Island Time

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Posted 20 August 2019 - 04:54 PM

IMO, that wont work. The exhaust will be well over 100c until AFTER the water injection, which is why the injection is normally above the rubber pipe connection.

 

However, I've never measured it on a diesel, so I dont know what it ought to be... 


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