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Author Topic: MTDI in a boat  (Read 19172 times)

Reply #90May 29, 2018, 01:46:28 pm

libbydiesel

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Re: MTDI in a boat
« Reply #90 on: May 29, 2018, 01:46:28 pm »
Fuel won't make its way to the exhaust.  Carbon will be present in the exhaust and when the engine is cold, you would likely get water condensation.  A mix of the two might be what you are seeing.  You might also get oil from the turbo if the drain is not properly done or if you have excessive crankcase pressure.   

Reply #91May 30, 2018, 01:37:20 am

LabradorSteak

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Re: MTDI in a boat
« Reply #91 on: May 30, 2018, 01:37:20 am »
I dont know about the crankcase pressure but the turbo should be draining properly.  I assume that if it was the turbo leaking that I would see some oil in the intake manifold.  Condensation could definately be it.

Thanks, I will update it if I figure anything out.

Matt.

Reply #92May 30, 2018, 01:56:09 am

libbydiesel

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Re: MTDI in a boat
« Reply #92 on: May 30, 2018, 01:56:09 am »
Can you post some pics of your oil return line?  Is there anywhere in the line that the ID is less than 3/8"?  Any p-trap valleys?  Does it enter the sump above oil level?  Is the drain within 15° of vertical (6:00)? 

Reply #93May 31, 2018, 12:24:54 pm

LabradorSteak

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Re: MTDI in a boat
« Reply #93 on: May 31, 2018, 12:24:54 pm »
I look at it a get some pictures today.

Matt.

Reply #94June 01, 2018, 03:11:57 am

LabradorSteak

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Re: MTDI in a boat
« Reply #94 on: June 01, 2018, 03:11:57 am »
Here is a picture of my oil drain from my turbo.  I ran the engine with some of the charge tubing off and held my hand over/infront of the turbo outlet and couldnt find any evidence of oil.  I also held a white rag over the outlet and didnt get any oil.  I sealed the exhaust manifold so I cant tell if there is still liquid coming out. 

The drain tubing uses all 1/2' fittings and hose.  It does sag and reenters the block where the stock oil return line did.


https://imgur.com/a/djTRNXm

Matt
« Last Edit: June 01, 2018, 03:15:03 am by LabradorSteak »

Reply #95June 01, 2018, 12:58:30 pm

libbydiesel

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Re: MTDI in a boat
« Reply #95 on: June 01, 2018, 12:58:30 pm »
That valley could be an issue.  It will always be filled with oil and even normal crankcase pressure can prevent it from draining properly.  The seals on the turbo shaft are not positive seals but rather like little piston rings and so if there is any issue with proper drainage, they will happily allow oil to pass freely. 

Here's a good video:  https://www.youtube.com/watch?v=5TYZChIdy14

Notice that he does not even raise the drain hose above the bottom of the center cartridge, and oil just pours out around the shaft.  Granted, the turbo in the video does not have a piston ring seal installed, but even with one installed, the oil would leak out around the shaft with a p-trap in the line. 

Reply #96June 03, 2018, 01:17:50 am

LabradorSteak

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Re: MTDI in a boat
« Reply #96 on: June 03, 2018, 01:17:50 am »
Thanks that was a very informative video.  I definately have a dip in my line.  I assumed that I was good because the line is bigger than stock but it is also longer.  I will keep an eye on the exhaust and oil level.  I pulled the charge tube and there wasnt any signs of oil on the wall of the tube.  Since I sealed the exhaust leak I am not able to easily see if the liquid is still there.  It will have to make it out to the turbo.  Hopefully I will be taking the boat to the river this weekend or early next week and it will get a full stress test.

Thanks, Matt.

Reply #97June 03, 2018, 03:46:17 pm

ORCoaster

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Re: MTDI in a boat
« Reply #97 on: June 03, 2018, 03:46:17 pm »
Stress it don't break it.  You have too much into it not to enjoy the fruits of your labor.

Reply #98June 03, 2018, 06:37:53 pm

libbydiesel

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Re: MTDI in a boat
« Reply #98 on: June 03, 2018, 06:37:53 pm »
I look forward to hearing about the results. 

Reply #99July 01, 2018, 11:09:35 pm

LabradorSteak

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Re: MTDI in a boat
« Reply #99 on: July 01, 2018, 11:09:35 pm »
I have the boat running but have only run it on the trailer on the ramp so far.  With the jet pump that I have hooked up to it I am only able to get 2500rpm with no boost showing on the gauge.  I may have the gauge hooked up wrong but when I have run the boat out of the water and no resistance on the engine I cant feel much if any air blowing out of the turbo.  I have a gt2052.  Should I be seeing boost by 2500rpm?  How can I make this turbo make more boost down around 2000-2200?

Thanks, Matt.

Reply #100July 01, 2018, 11:13:47 pm

LabradorSteak

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Re: MTDI in a boat
« Reply #100 on: July 01, 2018, 11:13:47 pm »
Also, will making more boost with the same amount of fuel result in less smoke or more smoke?  Right now it is smoking a little gray smoke at idle (more than I want).  There is soot on the back of the boat and the exhaust is exiting below the waterline so it is being filtered.

Matt.

Reply #101July 02, 2018, 08:29:07 pm

libbydiesel

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Re: MTDI in a boat
« Reply #101 on: July 02, 2018, 08:29:07 pm »
The amount of boost you make revving the engine without load will be minuscule compared to the same rpm under load. 

Reply #102July 03, 2018, 04:14:59 pm

LabradorSteak

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Re: MTDI in a boat
« Reply #102 on: July 03, 2018, 04:14:59 pm »
The maximum Egt I got was 740f and that was at full throttle for about one minute. I am thinking about turning the fuel screw up to see if it helps. How high is safe for constant running and how high should my limit be?

Matt.

Reply #103July 03, 2018, 04:57:36 pm

LabradorSteak

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Re: MTDI in a boat
« Reply #103 on: July 03, 2018, 04:57:36 pm »
Here is a short video of it running on the trailer

https://youtu.be/68V44fXAJdU

Matt

Reply #104July 03, 2018, 07:07:45 pm

libbydiesel

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Re: MTDI in a boat
« Reply #104 on: July 03, 2018, 07:07:45 pm »
Was that full throttle under load (propeller pushing water) or just in neutral?  Boost and EGTs will both be significantly different with the engine under LOAD than at the same rpms full 'throttle' in neutral.