Oil analysis after 110 hours tt 65 hours at 800 RPM

[garyd]

Well got the oil analysis back from the lab after calling them since it did not show up. Techy said looks very good kinda surprized. I'm not a chemist so here they are.

This oil analysis was from 110 hours of usage and at least 65 hours at 800 rpm and another 10-15 hours at 425-550rpm. The remaining hours were at 1776, 1850, 1901, and (2000, 2200 for very short runs less than 5 minutes).

625hp DDEC, props 25x29, 800 rpm 8.2 kts, 1776 rpm 22kts 1850 24kts 1901 rpm 25kts all loaded for vacation.

Once we got to Cat Cay we just went slow 600 rpm start up, 550 fast idle, 425 slow idle manuvering out of slip 550 rpm away from slip still in and around other boats/channel etc then 800 rpm for hours and hours till we arrived at our destination, then 550 rpm, then 425 rpm, then cool down and shut down. We did that for 2 and 1/2 weeks. Never went over 800 rpm.

Just before we got back to Cat Cay coming home I started to run it up to cruise rpm but had to stop around 1350 cause the dingy was starting to catch air. We were towing it. I slowly went from 800 to 1350 in 100 rpm increments. There was black smoke at each bump but it would clear pretty fast. The next day we left Cat Cay with the dink securley tied to the transom (weaver davits). After fully warmed up I slowly brought it to 1776 rpm. It did not smoke up through 1350 but then smoked at each 100 rpm interval up to 1776 at each interval the smoke cleared quickly and we stayed at 1776 rpm, smooth water at first and finished in 2'-4' waves.

We added no oil since the oil change. But it could of used two quarts per at the end but since I was going to change it anyway why waste a gallon of oil.



So here is the oil analysis average between engines. Almost all numbers were down compared to previous oil analysis's except Na which was about double what it has been in the past.

Al 2
Ca 2080
Cr 2.5
Cu 4
Fe 56
Pb 2
Mg 28.5
Mo 1
P 850
K 3
Si 10
Na 28
Sn 8
Zn 1060

WAF N v100 14.3

interesting v100 previous 15.3

Shell Rolla 40wt

So any of you'all with a great deal of oil analysis experience see anything bad about these numbers from going s l o w ?

 

[Diver Down]

I received an oil report on one of my 8v71Ts two weeks ago. My results were almost identical to your data. My sample was for 75 hours running most of the time at 1100-1400 RPM (with some warmup periods at idle). The narrative with my oil report states "This Detroit is just straight-up putting in work and not messing around. Period. Wear looks magnificent in this sample in spite of the fact that this oil was run significantly longer than the last oil was." The "longer" they referred to was number of months, not hours of run time.

 

[Brian Degulis]

On the electronics you shouldn't see any problems running slow. On the mechanical engines (run to slow) it will take quite a while to see the efects in the oil's condition.

Brian

 

[REBrueckner]

DD oil analyis standards are set at 150 hours run time. Your Na is out of spec, so I'd watch that one..all others looks good. If this is the only set of readings you have, I'd not do anything except sample again when you decide to change oil...

Anybody know what high Na (sodium) readings reflect?? Salt spray??

Here's a post of my own I found from almost three years ago:

The point is that lab results may not be precise and different labs pinpoint different readings. Also very few labs have the exact DD two cycle specs.

"You should search here at Sams for prior detailed discussions (on oil analysis) ...Among them is my post that one thousand hours ago I had a Cr reading of 12 on one engine at about 75 hours, which went unmentioned by one lab, and a current reading last fall around 7, and comparable hours, which was reported by another lab as "elevated". So how could rings get 'better' after 1,000 hours more use?? The point is you'll want to check and compare readings again at your next oil analysis...if that Cr reading creeps up, something maybe amiss...if it stays steady or decreases, I'd not be a worrywart...it's the trends over time that matter most.

 

[lumina]

Hi All,

We had an oil analysis done on both 8V71's three years ago and all came back clean, every component was right on or within tolerance. That was after our run from Ft Lauderdale to Mass.

We now have appx 250 additional hours on the engines and I had planned to do another test prior to haul out this year but got bogged down with issues so I missed that opportunity.

Is there ANY value to having one done now, on the hard. The block heaters are still on and the engine oil temp is appx 110 degrees

 

[rsmith]

Hi All,

We had an oil analysis done on both 8V71's three years ago and all came back clean, every component was right on or within tolerance. That was after our run from Ft Lauderdale to Mass.

We now have appx 250 additional hours on the engines and I had planned to do another test prior to haul out this year but got bogged down with issues so I missed that opportunity.

Is there ANY value to having one done now, on the hard. The block heaters are still on and the engine oil temp is appx 110 degrees

Needs to be done hot after a hard run so all the stuff is in suspension.Should fill the bottle half way thru the drain. So your not getting the top layer or bottom layer.

 

[TopHattandTails]

Anyone have the "specs" or" tolerances" for the 871ti's. Lab also says test results are normal. Would like to know what normal is.

 

[GJH]

Scroll down to page 4-8

http://extranet.detroitdiesel.com/pdf/vocations/Lube-Oil-Fuel-Requirements.pdf

 

[krush]

Just run it till it blows. The more hours you put on it, the longer it's going to last anyway!

 

[jim rosenthal]

Elevated sodium means your engine is dehydrated, or not getting enough water to drink, or you could be putting diuretics in the fuel tank

 

[rsmith]

110 hours tt 65 hours at 800 RPM= acid oil

 

[newinlet]

Just curious even if an oil sample showed high levels of this or high levels of that. If you did not have a major running issue with the engine ie oil in the water or such . Would you tear the engine down to investigate the possible issue based on an oil sample ?

 

[first big boat]

110 hours tt 65 hours at 800 RPM= acid oil

so I'm confused by your comment as it appears you also have a convertible. typical fishing day for me is running 2 hours out, troll at idle (800 rpm) for 6 hours and 2 hours back at 1900 rpm. so should I be changing my oil when? every 50 hours? I've always stood by 100 hours but based on you comment I am concerned.

 

[rsmith]

so I'm confused by your comment as it appears you also have a convertible. typical fishing day for me is running 2 hours out, troll at idle (800 rpm) for 6 hours and 2 hours back at 1900 rpm. so should I be changing my oil when? every 50 hours? I've always stood by 100 hours but based on you comment I am concerned.

I thought you were running 65 hrs straight. My misson profile is about the same.2 @ hrs out 8 hrs offshore and 2 hrs back in. I run 2100 IMO these engines need to be run hard to keep them clean and dry out the oil. The sulfur in the fuel turns to acid in the oil at low speeds. IMO the quality of fuel has degraded over the years and I dont belive the lo sulfur fuel realy is. I normaly go to the Bahamas every year and the fuel is clear as gin. After about a week of running the good stuff the brown haze behind the boat stops and the engines sound smoother the exhaust tone is more mellow.
Any way were stuck with what we got and the only way to be sure is with more regular changes. More if your not running the boat on a regular basis.