Help With Oil Analysis

The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.
See posts with no answers
fryedaze said:
3.5 gph at 7.8 knots. 1500 rpm.
I see I put 1500 hrs in OP instead of rpm
Approx 24,000 gal burned
Click to expand...

I'm assuming that’s for both engines. So about 370 gallons for that engine in 210 hours. That's a good amount fuel consumed for an oil interval. I like to figure oil changes as a calculation of gallons of diesel consumed per gallon of engine oil in the sump.

Ted
 
O C Diver said:
I'm assuming that’s for both engines. So about 370 gallons for that engine in 210 hours. That's a good amount fuel consumed for an oil interval. I like to figure oil changes as a calculation of gallons of diesel consumed per gallon of engine oil in the sump.



Ted
Click to expand...
What fuel number do you use? My change interval is set at 250 hrs, but with the north south migration, I always change before leaving MD and FL so I dont have to change in transit. I usually change between 180-210 hrs.
 
fryedaze said:
What fuel number do you use? My change interval is set at 250 hrs, but with the north south migration, I always change before leaving MD and FL so I dont have to change in transit. I usually change between 180-210 hrs.
Click to expand...

It's a very rough number, but around 100 gallons of diesel per 1 gallon of engine oil. That number is way below the manufacturer's number, but I'm going for long engine life. For most of the diesels I've owned, the oil is clean enough to see the marks on the dipstick without wiping the oil away.

Ted
 
O C Diver said:
It's a very rough number, but around 100 gallons of diesel per 1 gallon of engine oil. That number is way below the manufacturer's number, but I'm going for long engine life. For most of the diesels I've owned, the oil is clean enough to see the marks on the dipstick without wiping the oil away.



Ted
Click to expand...
So... (7.5gal X 100)/ 3.5gal/hr = 214.28 hrs . Close to the 250hr rec in the manual.
 
fryedaze said:
So... (7.5gal X 100)/ 3.5gal/hr = 214.28 hrs . Close to the 250hr rec in the manual.
Click to expand...

For my Dodge Cummins 6BT that holds 3 gallons of oil:

5,000 miles ÷ 20 MPG = 250 gallons of fuel

250 gallons of fuel ÷ 3 gallons of oil = 83 gallons of fuel per each gallon of oil in the crankcase. For me, it's how much soot I want to suspend in the oil before changing it.

Ted
 
O C Diver said:
For my Dodge Cummins 6BT that holds 3 gallons of oil:



5,000 miles ÷ 20 MPG = 250 gallons of fuel



250 gallons of fuel ÷ 3 gallons of oil = 83 gallons of fuel per each gallon of oil in the crankcase. For me, it's how much soot I want to suspend in the oil before changing it.



Ted
Click to expand...
For our boat it is 1400 miles÷2.2 mpg = 636 gal. Just providing data. Not arguing.
I changed my oil every 5K in a Honda 3.5L and used Mobile 1. Probably why it ran like a top when I traded it after 17 years and 230k miles. What RPM does that truck run at 60 mph??
 
You will be home soon. I no... creepy. Slow hand is in my Marine Traffic fleet.[emoji6] Screenshot_20220420-173827.jpg
Looks like you skipped the 22 oz steak.
 
Last edited:
I will ask Blackstone. I don't know the answer
This is the first time using them. I went through a Cat dealer before.
 
fryedaze said:
For our boat it is 1400 miles÷2.2 mpg = 636 gal. Just providing data. Not arguing.
I changed my oil every 5K in a Honda 3.5L and used Mobile 1. Probably why it ran like a top when I traded it after 17 years and 230k miles. What RPM does that truck run at 60 mph??
Click to expand...

Ok, but how many gallons of motor oil in the 2 engines? You take the 636 gallons of diesel consumed and divide that by the oil in the 2 engines. Think you will find you're around 100 gallons of fuel consumed for each gallon of oil in both engines.

Ted
 
fryedaze said:
Port engine analysis arrived. Same good story. Feeling good about my old girlsView attachment 127835
Click to expand...

Another good oil report!

At some point you might consider doing the transmissions. It will give you an idea of how the clutch plates and bearings are holding up. Also, if you see sodium (salt) starting to elevate, it's an early warning of the transmission cooler starting to leak raw water into the transmission oil.

Ted
 
O C Diver said:
Another good oil report!



At some point you might consider doing the transmissions. It will give you an idea of how the clutch plates and bearings are holding up. Also, if you see sodium (salt) starting to elevate, it's an early warning of the transmission cooler starting to leak raw water into the transmission oil.



Ted
Click to expand...
Good advice, I will do that this fall. All new coolers last year.
 
You must log in or register to reply here.

Similar threads

M
Analysis of DD 6V53 oil samples
Replies
7
Views
644
tiltrider1
tiltrider1
MVCalypso
Oil analysis lab recommendation?
Replies
22
Views
2K
MVCalypso
MVCalypso
Alaskan Sea-Duction
Oil Analysis on new Generator Engine
Replies
3
Views
477
BandB
BandB
markpj23
Heading To Survey - Marine Trader Items To Watch For?
Replies
6
Views
4K
Goldenruleinc
G
Leatherneck
Recommendations for an Oil Analysis Provider Needed
Replies
16
Views
907
O C Diver
O C Diver

Latest posts

Back
Top Bottom