Yanmar - Replacement Exhaust Elbow position


Dan Carlson
 

This is specifically for Amel SM owners with the Yanmar 4JH3-HTE engine who have replaced the Exhaust Elbow with the cast SS replacement.    (see attached photos)

 

I am planning to replace the ~1 meter exhaust hose that goes from the Exhaust elbow to the water separator.   When the mechanic looked at it his first question was “can the mounting be rotated 120 degrees so that it does not put such a bend in the exhaust pipe?”    So that is my question to this group. 

 

My replacement elbow is currently mounted with the exhaust exit vertical with a slight bend to the back of the engine, the water comes in from the front side.   If I rotated it 120 degrees, then the exhaust would exit more toward the back and greatly reduce the bend in the exhaust pipe.  The water would come in at a lower angle.   I don’t think that it would introduce any more risk of water back up into the turbo.  

 

Anyone have experience or knowledge related to this?

 

Thanks and regards,  Daniel Carlson, Amel SM #387, sv BeBe

             

 

 

 


eric freedman
 

Hi Dan,

Mine has been at that angle for the last 19+ years with no problem. I did have a metal water lift muffler made as my plastic one melted down.  You can move the muffler a bit for and aft to find a sweet spot for the hose. I also I had them change the angle on the muffler input slightly to reduce the bend in the hose.

 

Fair Winds

 

 

Eric

Kimberlite Amel Super Maramu #376

 

 

 

 

From: main@AmelYachtOwners.groups.io On Behalf Of Dan Carlson
Sent: Monday, July 19, 2021 11:43 AM
To: main@AmelYachtOwners.groups.io
Subject: [AmelYachtOwners] Yanmar - Replacement Exhaust Elbow position

 

This is specifically for Amel SM owners with the Yanmar 4JH3-HTE engine who have replaced the Exhaust Elbow with the cast SS replacement.    (see attached photos)

 

I am planning to replace the ~1 meter exhaust hose that goes from the Exhaust elbow to the water separator.   When the mechanic looked at it his first question was “can the mounting be rotated 120 degrees so that it does not put such a bend in the exhaust pipe?”    So that is my question to this group. 

 

My replacement elbow is currently mounted with the exhaust exit vertical with a slight bend to the back of the engine, the water comes in from the front side.   If I rotated it 120 degrees, then the exhaust would exit more toward the back and greatly reduce the bend in the exhaust pipe.  The water would come in at a lower angle.   I don’t think that it would introduce any more risk of water back up into the turbo.  

 

Anyone have experience or knowledge related to this?

 

Thanks and regards,  Daniel Carlson, Amel SM #387, sv BeBe

             

 

 

 


Dan Carlson
 

Thanks for the feedback Eric,

Structurally the hose is probably good for more years to come, but I'm having the cooling system serviced and while it's all disconnected I thought a new hose would be good. There is some corrosion in a few places where cracks in the hose have allowed air/moisture to corrode the wire inside the hose. And so the question is; if replacing, then why put such a tight bend back into the new hose. 

Thanks and regards, Daniel and Lori Carlson on sv BeBe, SM #387


On Mon, Jul 19, 2021, 8:05 PM eric freedman <kimberlite@...> wrote:

Hi Dan,

Mine has been at that angle for the last 19+ years with no problem. I did have a metal water lift muffler made as my plastic one melted down.  You can move the muffler a bit for and aft to find a sweet spot for the hose. I also I had them change the angle on the muffler input slightly to reduce the bend in the hose.

 

Fair Winds

 

 

Eric

Kimberlite Amel Super Maramu #376

 

 

 

 

From: main@AmelYachtOwners.groups.io On Behalf Of Dan Carlson
Sent: Monday, July 19, 2021 11:43 AM
To: main@AmelYachtOwners.groups.io
Subject: [AmelYachtOwners] Yanmar - Replacement Exhaust Elbow position

 

This is specifically for Amel SM owners with the Yanmar 4JH3-HTE engine who have replaced the Exhaust Elbow with the cast SS replacement.    (see attached photos)

 

I am planning to replace the ~1 meter exhaust hose that goes from the Exhaust elbow to the water separator.   When the mechanic looked at it his first question was “can the mounting be rotated 120 degrees so that it does not put such a bend in the exhaust pipe?”    So that is my question to this group. 

 

My replacement elbow is currently mounted with the exhaust exit vertical with a slight bend to the back of the engine, the water comes in from the front side.   If I rotated it 120 degrees, then the exhaust would exit more toward the back and greatly reduce the bend in the exhaust pipe.  The water would come in at a lower angle.   I don’t think that it would introduce any more risk of water back up into the turbo.  

 

Anyone have experience or knowledge related to this?

 

Thanks and regards,  Daniel Carlson, Amel SM #387, sv BeBe

             

 

 

 


Matt & Michelle Day, SM#208 SV Talia
 

Dan,

While I have dreams of one day being an AMEL expert, I have spent many years certifying engine installations (JD, CAT, Volvo and Yanmar) in heavy equipment.  To get a definitive answer to your question, you really must ask Amel/Yanmar.  When Amel contracted with Yanmar to use their engine (or Volvo for that matter) the Amel engineers had to submit an installation design based upon Yanmar's Installation Requirements Document (I believe it is at Revision 17.2.A).  Yanmar does a pre-installation review of the data submitted and provides a go/no-go decision.  The first Yanmar engine can then be shipped to Amel for test fit/install.  Amel then installs the engine, and Yanmar engineers show up and run a gazillion tests across typically 5-7 days (cooling, fuel flow, vibration, exhaust pressure diff, blah blah blah).  If the tests pass, Yanmar gives an Authorization to Supply, ships Amel engines, and stands behind their 2000Hr/2Yr warranty.  The point is to ensure the engineering design is maintained and will perform as expected. 

The orientation of the exhaust elbow will be in that cert document.  As will be the fuel line lengths, fuel pump model/placement, electrical harness length, key switch location, vibration model/mount, overflow size/location/height, exhaust hose size and length, intake size and length, etc/etc/etc/etc. All the sexy data is in that document....even the mass-spring spectrum graph....sweet! 

Does it matter?  The Japanese engine manufacturers DO NOT do random decision making.  The part is the way it is installed for a very specific reason in THIS INSTALLATION.  You have one data point that shows that it has not mattered based on how that boat has been operated.  Maybe there are risk mitigations that are overly conservative.  Maybe they just have not hit yet. The only way you will truly know is to ask Amel or your local Yanmar rep to look at the cert document.  Another option is to reach out to the Yanmar America Certification group in Adairsville Georgia.  They are good guys and may be willing to give you guidance or a definitive answer.

Matt
Talia - SM#208
Hampton, VA       


Paul Stascavage
 

Dan,

I hope all is well.

I recently replaced my entire exhaust hose and water lock. Based on a few suggestions from the group I went with the Vetus Slang Hose. I was happy with the choice and installing that short section was not difficult.

I cut the hose to the old hose length, attached it to the water lock first, then to the unattached exhaust elbow, and then install the elbow in the original position with the hose already attached. This product is relatively flexible.

All the Best,

Paul Stascavage
S/V Rita Kathryn SM #466

RitaKathryn.com

Currently Cruising New England