Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 07-11-2019, 04:35   #46
Registered User
 
Manana5's Avatar

Join Date: Jun 2018
Location: Greece
Boat: Wauquiez Centurion 32
Posts: 45
Re: Engine blues - volvo penta

Quote:
Originally Posted by Rhythmnblue View Post
Get it welded at a aluminium shop. This is what we did.
Yes, this is what we are doing as well. Will update if it works.
__________________

Manana5 is offline   Reply With Quote
Old 07-11-2019, 04:37   #47
Registered User
 
Manana5's Avatar

Join Date: Jun 2018
Location: Greece
Boat: Wauquiez Centurion 32
Posts: 45
Re: Engine blues - volvo penta

Quote:
Originally Posted by SOLAR SUPPORT View Post
Read again my post and take a look at the pictures.. The event is the same. Replace your elbow with a 316L Stainless Steel made one.
Yes, same issue! Thanks for sharing again. I didn't get from your post what you did about the holes in the main body? The elbow doesn't look that bad in our case so we won't be replacing it for now. Plus, wouldn't stainless steel next to aluminium cause MORE corrosion?
__________________

Manana5 is offline   Reply With Quote
Old 07-11-2019, 06:20   #48
Registered User

Join Date: Aug 2010
Location: Turkiye
Boat: Bavaria Match35 Meltemi
Posts: 15
Re: Engine blues - volvo penta

No. They are separeted with a gasket and there is no sea water splash back, if the elbow is made longer than the original one. I changed the damaged manifold. Because I couldn't find a trusted aluminium welding professional.
SOLAR SUPPORT is offline   Reply With Quote
Old 07-11-2019, 06:46   #49
Registered User

Join Date: Mar 2008
Posts: 5
Re: Engine blues - volvo penta

After welding, clean and sand the weld & the whole area. Apply JB Weld (high temp epoxy) to eliminate future corrosion.
Rhythmnblue is offline   Reply With Quote
Old 10-02-2020, 09:27   #50
Registered User

Join Date: Oct 2019
Posts: 9
Re: Engine blues - volvo penta

Hi,
same issue i had when i went to first pick my newly bought sailboat.
On a D1-30, radiator water was coming out from a small hole . When i took the part in my hands, i discovered few more...
I went to a welding shop and i have it repaired (welded fill) for 220euro.
The engine had no more than 800 hours, may of them just for charging.

I'm not sure if that gasket is electric good conductor, it seem metallic to me.
I was thinking to replace that gasket with something..i'm not sure what... sealing and stand quite high temps.

When the time will come for the exhaust elbow, i ll surely replace it with a stainless steel one, or i 'll order a custom made.




Attached Thumbnails
Click image for larger version

Name:	IMG_20191219_091320.jpg
Views:	24
Size:	113.7 KB
ID:	208412   Click image for larger version

Name:	IMG_20191223_104800.jpg
Views:	23
Size:	101.0 KB
ID:	208413  

Click image for larger version

Name:	IMG_20191223_104848.jpg
Views:	22
Size:	105.0 KB
ID:	208414  
kostasc is offline   Reply With Quote
Old 10-02-2020, 23:31   #51
Registered User

Join Date: Aug 2010
Location: Turkiye
Boat: Bavaria Match35 Meltemi
Posts: 15
Re: Engine blues - volvo penta

This is the galvanic corrosion. The reason of this is the iron cast elbow next to aluminium exhaust housing. Gasket is the innocent part that has no role in this corrosion event.

The iron cast elbow gets rusted very fast since the salty water and exhaust gas passed through it when the engine runs. It is like puting an iron in to the sea water. Then liquid and gas flow through this elbow become irregular, because of the rust deposits on the gas and sea water flow surfaces in the elbow(mixer). Sea water starts to splash back drops to the aluminium exhaust housing.

When you put two or more different metals like aluminium and iron close to each other in a closed housing and splash some salty water on them, galvanic corrosion occur even if you install a thin gasket between them.

This is a common problem for each Volvo Penta D1-20, D1-30, D1-40 engine. When you look at to Yanmar engine at this point, they use a longer stainless steel elbow instead of an iron cast short elbow. This is the most important differance between the two brands which makes Yanmar more preferable and reliable.

This video shows a tuned 316L stainless steel elbow installation to D1-30 engine of my boat.

https://youtu.be/gwKlZlgI6u8
SOLAR SUPPORT is offline   Reply With Quote
Old 10-02-2020, 23:43   #52
Registered User

Join Date: Mar 2018
Location: New Zealand
Boat: 50’ Bavaria
Posts: 1,620
Re: Engine blues - volvo penta

This is what I don't really understand. I've had three Volvo Pentas (admittedly none of the more recent Dx-xx models), but all of them have had very similar cast iron exhaust elbows as these ones. Between 5 and 25 years old, they've shown bits of corrosion in the elbow but nothing a bit of phosphoric and a wash didn't get rid of. Never seen anything like these horrendous cratering situations. What is it that causes such major problems in these elbows when some engines don't have the problem at all?
Tillsbury is offline   Reply With Quote
Old 11-02-2020, 01:34   #53
Registered User

Join Date: Aug 2010
Location: Turkiye
Boat: Bavaria Match35 Meltemi
Posts: 15
Re: Engine blues - volvo penta

The same iron cast elbow is being used with D1-20, D1-30, D1-40 VP engines. If your's is different then it might be normal for you to observe any problem with iron cast elbow~aluminium cast exhaust housing's galvanic corrosion.

Since sail drive mount of these series of engines positioned more horizontal to the sea waterline the problem should be seen soon when compared with direct shaft-propeller installations for those have a small angle with the motor and shaft togeather with the sea waterline that makes harder for splashing back sea water drops to the exhaust housing when they were runing.
SOLAR SUPPORT is offline   Reply With Quote
Old 11-02-2020, 02:49   #54
Registered User

Join Date: Oct 2019
Posts: 9
Re: Engine blues - volvo penta

That was my initial thought, the water drop/sprayed back, but the design of the exhaust elbow is not allowing that. Raw water is sprayed on the outer part of the inner elbow wall. So the water is present at the end part of the elbow, 3-4 cm before elbow end. If there is always a one way exhaust fume, and no reason for water return, why any drops are coming back?
I ve heard issues with engines just under 600 hours ! so soon to say carbon deposit are blocking exit.
If sea water is the catalyst for this, why not solving the elbow's cooling issues with an external cooling coil (or something like this) and inject water few cm after elbow at a safe distance ?
This is a major fault from Volvo, Perkins, Su... something who designed these engines.
kostasc is offline   Reply With Quote
Old 11-02-2020, 04:13   #55
Registered User

Join Date: Aug 2010
Location: Turkiye
Boat: Bavaria Match35 Meltemi
Posts: 15
Re: Engine blues - volvo penta

There are two pipes within the iron cast elbow surrounding each other. Sea water coolant comes from the heat exchanger being poured in between these pipes to their top at the starting of the closed exhaust housing and elbow joint. The sea water coolant cools the inner exhaust pipe and the joint.

Exhausted gases coming from the runing motor's cylinders exhausted from the inner pipe. The coolant sea water and the exhaust gases ere mixed just four or five cm. after the elbow and exhaust housing joint.

This short distance is not enough when the motor is idling or runing at low rpms specialy when the cast iron elbow gets rusted and leads to nonlaminar flow of both the sea water coolant and the exhaust gases within the elbow. Rusting of the cast iron elbow is being very fast. VP services recommend to check the iron cast elbow each year. If it is cloged then replace it with the new elbow.

By using a different technique to bond longer curved pipes within the elbow like welding rather than casting and using the right material like 316L SSteel, solve this problem. Making longer sea water coolant passage within the elbow guarantee no sea water splash back to aluminium cast exhaust housing. No more galvanic corrosion.

I have used mine 250 hours after the elbow change, even at idle speeds for charging my batteries and at low rpms around 1700 when troling. No problem at all.
__________________

SOLAR SUPPORT is offline   Reply With Quote
Reply

Tags
engine, penta, volvo

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
'02 Volvo Penta Engine S Campbell Engines and Propulsion Systems 93 12-10-2019 23:19
A Recent Marine Survey / Engine Survey in Fort Lauderdale of a Volvo-Penta Engine SuenosAzules Powered Boats 5 25-11-2016 07:17
Loss of Power - Inboard Volvo Penta Diesel Engine Kiwi@Sea Engines and Propulsion Systems 6 24-11-2011 09:24
For Sale or Trade: Volvo-Penta MD6B Marine Diesel Engine woodymr Classifieds Archive 5 02-10-2010 19:44
Volvo Penta Diesel Engine Is Hard to Start wsvoboda Engines and Propulsion Systems 13 14-02-2010 19:16

Advertise Here


All times are GMT -7. The time now is 23:34.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.