Reply
 
Thread Tools Search this Thread Display Modes
 
Old 04-01-2018, 11:07 AM   #1
Guru
 
City: gulf coast
Country: pinellas
Join Date: Jun 2014
Posts: 2,802
How quickly does your diesel lube oil go black?

I have read claims that people's diesel lube oil stays cler for quite a while but after owning three diesels I have never seen oil stay clean looking very long at all.
What are your experiences?
__________________
Advertisement

bayview is online now   Reply With Quote
Old 04-01-2018, 11:24 AM   #2
Guru
 
Ski in NC's Avatar
 
City: Wilmington, NC
Country: USA
Vessel Name: Louisa
Vessel Model: Custom Built 38
Join Date: Jan 2014
Posts: 5,359
Depends on the engine and the loading. Some 3208TA in high output apps you can change the oil three times in a row and it is black after a couple hours run. Run same engine at 1200 and it will stay clean for 20hrs.

Nothing wrong with black oil, it's just soot.

On my 450C, it is pretty black at 50-100hrs, I change it at about 300hrs.

If it bothers you, take a sample and see what the soot/insolubles are.
__________________

Ski in NC is online now   Reply With Quote
Old 04-01-2018, 11:42 AM   #3
Guru
 
MYTraveler's Avatar
 
City: West Coast
Country: USA
Join Date: Apr 2014
Posts: 1,081
QSM11's, which I have owned since new, turn the oil black in about 24 hours run time, even though engines are run below 1100 rpm more than 90% of the time.
MYTraveler is online now   Reply With Quote
Old 04-01-2018, 12:19 PM   #4
Guru
 
Ken E.'s Avatar
 
City: Bellingham WA
Country: United States
Vessel Name: Hatt Trick
Vessel Model: 45' Hatteras Convertible
Join Date: Nov 2016
Posts: 964
Cummins 6bt's.....The oil is pretty black after 10 hours of running them easy. Ironically, I've had 2-cycle Detroits that didn't turn black until 50 hours or so.
Ken E. is online now   Reply With Quote
Old 04-01-2018, 12:39 PM   #5
Guru
 
C lectric's Avatar
 
City: B.C.
Country: Canada
Vessel Name: Island Pride
Vessel Model: xxxx
Join Date: Oct 2007
Posts: 2,478
Mine used to blacken the oil fairly quickly. THe oil still blackens but it now takes a few more hours. By 40 or so it's black.
C lectric is online now   Reply With Quote
Old 04-01-2018, 02:04 PM   #6
Guru
 
Comodave's Avatar
 
City: Au Gres, MI
Country: US
Vessel Name: Never Say Never
Vessel Model: President 41 DC
Join Date: Jul 2015
Posts: 5,795
My Lehmans turn it black pretty quickly.
Comodave is online now   Reply With Quote
Old 04-01-2018, 03:32 PM   #7
Guru
 
Lepke's Avatar
 
City: Between Oregon and Alaska
Country: US
Vessel Name: Charlie Harper
Vessel Model: Wheeler Shipyard 83'
Join Date: Jun 2016
Posts: 1,615
I run clean oil. I centrifuge the oil every 25-50 hours. Before the centrifuge I used add on bypass filters. I've been experimenting with running clean oil since the 1960s and my experience shows much longer engine life. Maybe more than double if you're not running high exhaust gas temperatures.
With filtering, the slower oil passes thru a filter, the more dirt it traps. That why many Detroit Diesels have transparent oil longer. Older DDs had a bypass filter and no full flow filter. Later they had dual full flow filters that slowed the flow. Many small diesels come with short spin on filters, but a longer version is usually available. Going to the longer size cuts the flow rate almost in half and catches more debris.
Fine soot eventually clumps into larger particles along with other debris and gets to a size where it causes engine wear before a full flow filter can capture the dirt.
I haven't actually changed oil for more than 5 years, just add make up oil and test 1-2 times a year. The centrifuge also removes water.
Lepke is offline   Reply With Quote
Old 04-01-2018, 04:03 PM   #8
Veteran Member
 
TugYacht_33's Avatar
 
City: Fayetteville
Country: USA
Vessel Name: Mhyzhen
Vessel Model: Custom 33' Glen-L design "union jack"
Join Date: Nov 2017
Posts: 81
Lepke,
could you please do a thread on the centrifuge....
what it is, how it works, etc....
and let us know your findings and thoughts etc...

are they readily available, something you made yourself, expensive as all hell?

you know, just everything about it, lol

thank you! and now back to the present thread
__________________
"busted knuckles"..... one more and i will have a complete set !
TugYacht_33 is offline   Reply With Quote
Old 04-01-2018, 04:13 PM   #9
Guru
 
djmarchand's Avatar
 
City: Litchfield, Ct/Punta Gorda, Fl
Country: USA
Vessel Model: Atlas Pompano 23
Join Date: Aug 2012
Posts: 4,854
I too would like to see more discussion about centrifuging oil. I suspect, but have nothing to back it up, that most soot is very fine, will not get trapped by the filter and will not be removed by centrifuging.

I accept Lepke's statement above that the small soot particles can clump and then can cause engine wear. But at that point won't they get trapped by the filter. And won't the dispersants in the oil keep the soot from clumping?

David
djmarchand is offline   Reply With Quote
Old 04-01-2018, 04:16 PM   #10
Guru
 
Ken E.'s Avatar
 
City: Bellingham WA
Country: United States
Vessel Name: Hatt Trick
Vessel Model: 45' Hatteras Convertible
Join Date: Nov 2016
Posts: 964
Maybe Lepke or Ski could also explain the merits of bypass filtration, how widely it's used in boats etc. I understand long haul trucks usually have these installed.
Ken E. is online now   Reply With Quote
Old 04-01-2018, 04:33 PM   #11
Guru
 
Simi 60's Avatar
 
City: Queensland
Country: Australia
Vessel Model: Milkraft 60 converted timber trawler
Join Date: Jul 2016
Posts: 2,218
NTA855 Cummins.
Oil was clear when I last dropped it
Has 150 hours on it now and still clear.
Simi 60 is online now   Reply With Quote
Old 04-01-2018, 04:38 PM   #12
Guru
 
Simi 60's Avatar
 
City: Queensland
Country: Australia
Vessel Model: Milkraft 60 converted timber trawler
Join Date: Jul 2016
Posts: 2,218
Quote:
Originally Posted by Lepke View Post
I Many small diesels come with short spin on filters, but a longer version is usually available. Going to the longer size cuts the flow rate almost in half and catches more debris.
I am installing a remote oil filter to my Kubota based genset
This will allow not only easy change but fitment of much larger filters
Oil has always been instantly black after change so it'll be interesting to see what results I get with a bigger filter.
Simi 60 is online now   Reply With Quote
Old 04-01-2018, 05:12 PM   #13
Guru
 
High Wire's Avatar
 
City: Cape May, NJ and Englewood, FL
Country: USA
Vessel Name: Irish Lady
Join Date: Dec 2007
Posts: 2,813
1984 Perkins 6.3544 NA. Still transparent at 200 hours. It takes about 50 hours and a good light to see the level on the dipstick. The Perkins uses Rotella T5 10W30. My old Westerbeke gen would be black at 40-50 hours with same 10W30. New Phasor gen still transparent at first 50 hour change but darker than the Perkins at 200. No clue what the factory put in the Phasor. 1st oil change was with Rotella T5 10W30. Using NAPA Gold filters on all.
__________________
Archie
1984 Monk 36 Hull #46
Currently southbound in Georgia.
High Wire is offline   Reply With Quote
Old 04-01-2018, 06:03 PM   #14
Guru
 
Lou_tribal's Avatar
 
City: Quebec
Country: Canada
Vessel Name: Bleuvet
Vessel Model: Custom Built
Join Date: Jan 2016
Posts: 3,516
Quote:
Originally Posted by Lepke View Post
I run clean oil. I centrifuge the oil every 25-50 hours. Before the centrifuge I used add on bypass filters. I've been experimenting with running clean oil since the 1960s and my experience shows much longer engine life. Maybe more than double if you're not running high exhaust gas temperatures.
With filtering, the slower oil passes thru a filter, the more dirt it traps. That why many Detroit Diesels have transparent oil longer. Older DDs had a bypass filter and no full flow filter. Later they had dual full flow filters that slowed the flow. Many small diesels come with short spin on filters, but a longer version is usually available. Going to the longer size cuts the flow rate almost in half and catches more debris.
Fine soot eventually clumps into larger particles along with other debris and gets to a size where it causes engine wear before a full flow filter can capture the dirt.
I haven't actually changed oil for more than 5 years, just add make up oil and test 1-2 times a year. The centrifuge also removes water.
Doesn't oil also accumulate acidic combustion byproduct (other than soot) that makes it damageable beyond a certain concentration?

L
Lou_tribal is offline   Reply With Quote
Old 04-01-2018, 06:04 PM   #15
Senior Member
 
bshanafelt's Avatar
 
City: Seattle, WA
Vessel Name: Isobel K
Vessel Model: 37' Custom Pilothouse
Join Date: Oct 2007
Posts: 312
I use a Gulf coast bypass filter on my Cummins 6bt .

Filter element is nothing more than a large size bounty paper towel roll.


Change the filter every 100 hrs & add about a gallon of make up oil

I do a full oil change at 7-800 hrs.

Oil is tested every year.

The oil color stays almost clear which I understand is lack of soot

I
bshanafelt is offline   Reply With Quote
Old 04-01-2018, 07:04 PM   #16
Guru
 
AusCan's Avatar
 
City: Adelaide
Country: Australia
Vessel Name: Kokanee
Vessel Model: Cuddles 30 Pilot House Motor Sailer
Join Date: Jul 2012
Posts: 2,893
Quote:
Originally Posted by Lou_tribal View Post
Doesn't oil also accumulate acidic combustion byproduct (other than soot) that makes it damageable beyond a certain concentration?

L
I agree, Lou.

Besides soot, there are many factors which will limit oil life.
Increased acidity, decreased alkalinity reserve (TBN), changes in viscosity, oxidization, moisture or diesel contamination, silicon contamination, etc.

High oil acidity can be particularly damaging on engines that sit for extended periods without running.

Soot is more visible than the other issues, but I'd be more concerned about the things you can't see.
AusCan is offline   Reply With Quote
Old 04-01-2018, 07:28 PM   #17
Guru
 
City: Sydney
Country: Australia
Join Date: Jul 2015
Posts: 1,646
Quote:
Originally Posted by Ken E. View Post
Cummins 6bt's.....The oil is pretty black after 10 hours of running them easy. Ironically, I've had 2-cycle Detroits that didn't turn black until 50 hours or so.




50 hours on my 6bts since oil change and its still clean
gaston is offline   Reply With Quote
Old 04-01-2018, 08:09 PM   #18
Guru
 
BruceK's Avatar
 
Join Date: Oct 2011
Posts: 9,990
When I DIY change it with a pissy little pump, it gets dirty quickly. When the mechanic does it with his vacuum sucker which he leaves connected overnight,the fresh oil stays nice and clean.
__________________
BruceK
Island Gypsy 36 Europa "Doriana"
Sydney Australia
BruceK is offline   Reply With Quote
Old 04-01-2018, 08:27 PM   #19
Guru
 
O C Diver's Avatar
 
City: Fort Myers, FL... Summers in Crisfield, MD
Country: USA
Vessel Name: Slow Hand
Vessel Model: Cherubini Independence 45
Join Date: Dec 2010
Posts: 7,624
My Cummins 6bt 200 HP in my Dodge pickup stays clear on the stick till oil change (100 hours 5,000 miles). It only burns 2.5 GPH at hiway cruise. The Cummins 6ct 300 HP in my charter boat turns black on the stick at 15 hours. It burns 12 gallons an hour. I change the oil at 50 hours. It uses no oil between 0 and 50 hours. At 75 hours it's burning a quart every 6 hours. At 100 hours it's burning 2 quarts every 6 hours. I don't fully understand why it starts using oil after 50 hours. So I just change it at 50 hours. To put things in perspective, oil and filter runs about $100. 12 gallons per hour for 50 hours will be about $1,500 to $1,800 this summer. So oil changes are cheap by comparison.

Regarding additional oil filters and refining your used motor oil, I feel oil and filters are relatively cheap and am happy paying for new oil each time.

Ted
__________________
Blog: mvslowhand.com
I'm tired of fast moves, I've got a slow groove, on my mind.....
I want to spend some time, Not come and go in a heated rush.....
"Slow Hand" by The Pointer Sisters
O C Diver is online now   Reply With Quote
Old 04-01-2018, 08:54 PM   #20
Senior Member
 
Gabe n Em's Avatar
 
City: Point Judith, RI
Country: USA
Vessel Name: In Sanity
Vessel Model: 1981 Mainship 40'
Join Date: Jan 2015
Posts: 408
Our perkins stay clear for a little while, maybe 20 hours? but by the 100 hour mark when we change it, its jet black. There's no oil consumption and the annual analysis have all come back happy.

I'd be wary of a centrifuge system because I want the oil additives to be cleaning. I believe in better living through chemistry, but there's snake oil to be wary of. ...what I'm saying is, is: I dunno
__________________

Gabe n Em is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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





All times are GMT -5. The time now is 04:40 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012
×