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10-25-2020, 10:58 AM
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#1
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Senior Member
City: Lagrange, IL
Vessel Name: Moondance
Vessel Model: Grand Banks CL 42
Join Date: Sep 2019
Posts: 214
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CAT 3208 failure - how to prevent next time
Looking seriously at GB42 with CAT 3208 (435HP). Engines are rebuilt and have low hours. Original stb engine went bad due to aftercooler issue - water into the engine -don't have the exact story but I sure don't want to have the same issue. PO decided to replace port engine at the same time. This was BIG BIG $$ and I saw the invoices. So I know you have to keep up with scheduled maintenance and oil analysis but what else do you/can you do to prevent this type of catastrophic failure? Are there any type of gauges one might install?
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10-25-2020, 11:12 AM
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#2
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Guru
City: Sea of Cortez, Mexico
Vessel Name: Irene
Vessel Model: Nordhavn 40II
Join Date: Jan 2016
Posts: 1,234
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I have not owned those, but would expect them to be exceedingly reliable with diligent maintenance, regular and appropriate use, and some good monitoring via oil analysis and an occasional Cat technician visit.
Seems like you are exercising due diligence based on your other posts. Were you able to attend the engine survey and chat up the Cat technician?
Have you been over to boatdiesel.com yet? It’s a technical forum with a tremendous library of data available for subscribers. You could read the 3208 posts for days.
As others have mentioned, don’t run it “on the pins” continuously or overheat them. DO run them up occasionally to verify WOT RPM, heat them up, clear them out.
You may have found a diamond in the rough with that essentially repowered boat. You may have more concern with fuel tanks and teak decks than those engines at this point (hopefully none of it).
__________________
Jeff
MV IRENE
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10-25-2020, 11:17 AM
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#3
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Guru
City: Sea of Cortez, Mexico
Vessel Name: Irene
Vessel Model: Nordhavn 40II
Join Date: Jan 2016
Posts: 1,234
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3208 435HP E rating
High Performance - For vessels operating at rated load and rated speed up to 8 percent of the time, or one half hour out of 6, (up to 30 percent load factor). Typical applications could include but are not limited to vessels such as pleasure craft, harbor patrol boats, harbor master boats, some fishing or patrol boats. Typical operation ranges from 250 to 1000 hours per year.
__________________
Jeff
MV IRENE
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10-25-2020, 11:18 AM
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#4
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Guru
City: gulf coast
Join Date: Jun 2014
Posts: 3,440
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Some boat makers do not install proper exhaust systems. Exhaust should be designed so that any failure of the water jacket will not drain back into the engine. Boat builders design, or at least choose, and install the exhaust not the engine maker.
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10-25-2020, 11:23 AM
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#5
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Guru
City: Sea of Cortez, Mexico
Vessel Name: Irene
Vessel Model: Nordhavn 40II
Join Date: Jan 2016
Posts: 1,234
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I see you are on boatdiesel.
__________________
Jeff
MV IRENE
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10-25-2020, 11:30 AM
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#6
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Guru
City: Inside Passage Summer/Columbia River Winter
Vessel Name: Alaskan Sea-Duction
Vessel Model: 1988 M/Y Camargue YachtFisher
Join Date: Jul 2012
Posts: 8,046
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I have the 3208 T/A 375hp. According to CAT they recommend running the engines at 80% RPM of WOT. For me that's around 2240.
I run my engines at 2100 on a regular bases. I do Astoria to Neah Bay in 12 hours at these RPMs which is about 190sm.
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10-25-2020, 12:06 PM
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#7
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Guru
City: Pender Harbour, BC
Vessel Name: Gwaii Haanas
Vessel Model: Custom Aluminum 52
Join Date: Sep 2013
Posts: 3,791
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Check out https://www.sbmar.com/
They mostly do Cummins but there are very good articles/advice by Tony Athens on what to look for in marine exhaust (plus other excellent articles not specific to Cummins). Using Tony's knowledge should give you a yardstick to evaluate your installation.
The GB 42 in later years was bastardized into a sort of strange boat that would go much faster than it was designed for, threw a wake like a destroyer and generally would go about 25 knots wot while consuming vast amounts of fuel. It had to have strakes screwed to the hull otherwise you couldn't see out the windows. Not dignified at all like my lovely 32 with 120 hp., hence my curmudgeonly attitude to the later 42s!
The basic naturally aspirated 3208s are lifetime engines but by doubling the horsepower their longevity suffered. Some Cat blocks were not rebuildable but as I'm attached to a Cummins now, I have no idea which.
Check out Tony's stuff.
__________________
Don't believe everything that you think.
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10-25-2020, 06:07 PM
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#8
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Guru
City: Gibsons, B.C., Canada
Vessel Name: Island Pride
Vessel Model: Palmer 32'
Join Date: Oct 2007
Posts: 4,409
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Aftercoolers need to be pulled ,cleaned, pressure tested every 2-3 years.
Lots of info on Boatdiesel along with a fellow called dave. Note the lower case spelling. dave is a Cat expert who gives a lot of time there. DO a search for his posts. Pose the question about replacement time for the aftercoolers as they do have a definite lifetime.
Note the time is years , not hours as corrosion and fouling don't heed hours meters.
Correct propping is needed on boats with engines like these where there is any likelyhood of planing the boat. THe engines must be able to reach full rpms or they are overloaded and will suffer. You will get all kind of arguement about deliberate overpropping which is fine if you NEVER attempt a high power blast but if you plan on using the boat as a planing boat beware.
You ask about guages to help prevent problems.
--Boost
--EGT measure exhaust temp and will tell you very quickly how hard you are pushing the engines. Especially if too hard.
--one alarm in addition to what you have while you are thinking about this is a loss of raw water alarm.
If you go for the boat then some more questions about these can be answered.
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10-25-2020, 06:12 PM
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#9
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Moderator Emeritus
City: Au Gres, MI
Vessel Name: Black Dog
Vessel Model: Formula 41PC
Join Date: Jul 2015
Posts: 21,129
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I believe that this is the highest HP rating that these engines have. The NA versions will seemingly run forever. As the HP ratings go up life goes down. If they are run at a reasonable level they will last a long time too. But they do need the routine maintenance done. Good luck with the boat if you proceed with the purchase. And of course we will need photos if you do buy it...
__________________
Boat Nut:
If you are one there is no explanation necessary.
If you aren’t one, there is no explanation possible.
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10-25-2020, 06:27 PM
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#10
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Valued Technical Contributor
City: Litchfield, Ct
Join Date: Aug 2012
Posts: 6,775
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The POs original problem seems to be from lack of after cooler maintenance not running the engines too hard. But you can wear those engines out if you run them at 90% of wot rpm, 90% of the time.
I don't know anything specific about Cat 3208 aftercoolers, but I can extrapolate from Cummins and Yanmar. Read Tony Athens' articles in the Tony's Tips section of sbmar.com. Basically you should remove, disassemble, clean, reassemble with lots of grease and pressure test your after coolers every 3 years or so. If you do that, you are very unlikely to ever have any after cooler problems.
David
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10-25-2020, 06:29 PM
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#11
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Moderator Emeritus
City: Au Gres, MI
Vessel Name: Black Dog
Vessel Model: Formula 41PC
Join Date: Jul 2015
Posts: 21,129
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On my engines I didn’t know the history of the aftercooler maintenance so I bypassed them so now I don’t have to worry about maintaining them. I don’t need or have ever used the extra power.
__________________
Boat Nut:
If you are one there is no explanation necessary.
If you aren’t one, there is no explanation possible.
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10-25-2020, 06:51 PM
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#12
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Senior Member
City: Lagrange, IL
Vessel Name: Moondance
Vessel Model: Grand Banks CL 42
Join Date: Sep 2019
Posts: 214
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Quote:
Originally Posted by Comodave
On my engines I didn’t know the history of the aftercooler maintenance so I bypassed them so now I don’t have to worry about maintaining them. I don’t need or have ever used the extra power.
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Now that is interesting . Do I assume you also bypass the turbos? Tell me more as how you do this. I don't think I will need the 435HP either. I just like the boat and that it is newer (for a GB42 that is). But I don't think they put a lot of smaller powered engines in these newer boats so it is a compromise for me.
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10-25-2020, 07:03 PM
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#13
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Guru
City: Rochester, NY
Vessel Name: Hour Glass
Vessel Model: Chris Craft 381 Catalina
Join Date: Aug 2019
Posts: 7,538
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I wouldn't try to depower the engines. You should have the fueling turned down and bypass the aftercoolers, but I don't see a good reason to do it. And I don't think there was ever a turbo 3208 with no aftercooler.
The high power 3208s will burn the same fuel as a lower powered version when going slow. They'll only burn more fuel when you use the power. As long as the aftercoolers are maintained, I don't see them as a big risk.
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10-25-2020, 07:58 PM
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#14
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Moderator Emeritus
City: Au Gres, MI
Vessel Name: Black Dog
Vessel Model: Formula 41PC
Join Date: Jul 2015
Posts: 21,129
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Mine are a bit different animal than the Cats. I still have the turbos. But on my engines all I had to do to bypass the aftercooler was to unhook the cooling water going in and coming out of the aftercoolers and run a hose around them. It took about 15 minutes per engine and I can go back almost as easily. On mine I didn’t have to adjust the fueling or injector pump at all.
__________________
Boat Nut:
If you are one there is no explanation necessary.
If you aren’t one, there is no explanation possible.
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10-26-2020, 08:42 AM
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#15
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Senior Member
City: Hobe Sound
Vessel Name: Kumatage
Vessel Model: Grnd Bnks 46 cl
Join Date: Aug 2020
Posts: 229
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Quote:
Originally Posted by Comodave
Mine are a bit different animal than the Cats. I still have the turbos. But on my engines all I had to do to bypass the aftercooler was to unhook the cooling water going in and coming out of the aftercoolers and run a hose around them. It took about 15 minutes per engine and I can go back almost as easily. On mine I didn’t have to adjust the fueling or injector pump at all.
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I've been wondering about doing the same thing on my 3208s. Does the cooler make that much difference? That boost air is being pushed in pretty quickly.
I was also pondering an air cooled heat sink type of arrangement with aluminum fins.
Thoughts?
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10-26-2020, 08:50 AM
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#16
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Guru
City: gulf coast
Join Date: Jun 2014
Posts: 3,440
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Quote:
Originally Posted by Steve1.0
I've been wondering about doing the same thing on my 3208s. Does the cooler make that much difference? That boost air is being pushed in pretty quickly.
I was also pondering an air cooled heat sink type of arrangement with aluminum fins.
Thoughts?
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The maker must have installed aftercoolers just for fun.
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10-26-2020, 10:59 AM
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#17
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Senior Member
City: Hobe Sound
Vessel Name: Kumatage
Vessel Model: Grnd Bnks 46 cl
Join Date: Aug 2020
Posts: 229
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Bayview, brilliant!
Any other words of wisdom?
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10-26-2020, 11:41 AM
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#18
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Valued Technical Contributor
City: Litchfield, Ct
Join Date: Aug 2012
Posts: 6,775
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After coolers do make a difference but usually at higher rpms. At wot when the engine is making full power, the air from the turbo charger can be compressed to 3-500 degrees more than ambient inlet air. If that heat is not removed then the valves will fry and/or the piston will melt due to vary high EGTs, well over the design EGT value.
But if you run the engine at lower rpms and loads, say 600 rpm off of top you should be ok if you reroute the raw water to bypass the after cooler.
Even better would be to look at other Cat 3208s and see if one model doesn't use coolant to cool the after cooler. This type of after cooler is used on turbo charged car engines. You may have to upgrade the raw water cooled heat exchanger because if you do this it will now be putting more btu/hr load on the coolant system. But if there is a Cat 3208 model with coolant cooled after cooler then use its exchanger specs and coolant flow path. Also look at the coolant pump and see if it is bigger on the coolant cooled after cooler engine.
Coolant cooled after coolers have a fraction of the problems as raw water cooled ones.
This will also require you to run at much less than wot rpm as coolant won't cool the air as well as raw water. So maybe 400 rpm off of top will be ok.
And finally you really should recalibrate the injection pump or use a different pump if you are going to change it from raw water after cooling so you can never run at the original wot rpms.
Those figures are all educated guesses.
David
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10-26-2020, 10:44 PM
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#19
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Guru
City: hawaii
Vessel Name: #31
Vessel Model: ex-Navy MUB 50 fish/cruise
Join Date: Aug 2013
Posts: 869
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You can cut down on raw water aftercooler maintainence by diligently flushing with fresh water after use.
This doesn’t make them maintenance free, but can extend service interval, and is beneficial to the entire raw water system.
__________________
You can lead a horse to water,
But you can't make him ski...
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10-27-2020, 08:27 AM
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#20
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Senior Member
City: Hobe Sound
Vessel Name: Kumatage
Vessel Model: Grnd Bnks 46 cl
Join Date: Aug 2020
Posts: 229
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[QUOTE=DavidM;936658]After coolers do make a difference but usually at higher rpms. At wot when the engine is making full power, the air from the turbo charger can be compressed to 3-500 degrees more than ambient inlet air. If that heat is not removed then the valves will fry and/or the piston will melt due to vary high EGTs, well over the design EGT value.
Wow, 3-500 degrees! New respect for the after cooler.
Thanks for that David.
I just reinstalled mine after cleaning the built up crud from the fins. PO never did any maintenance as far as I could tell. I'll post a few pics.
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