Used oil to power our diesel boats

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RickyD

RickyD

Guru
Joined
May 4, 2018
Messages
803
Location
United States
Vessel Name
Aquarius
Vessel Make
Californian 55 CPMY
Just a passing thought here. Since our engines run on many fuels, what would happen if, after changing my oil, I poured the old oil into my fuel tanks. I hold 400 gallons in one and 250 in another. Could guess that I might clog the fuel filters faster, but what else? 5 gallons into 400 is well diluted.
 
i too was wondering about that for a long time.

Being from California i always feared that someone will tell the local Enviromental police:angel:

let us know how that works.
 
Years ago I remember reading that Cummins said you could burn up to 5% waste oil. Today’s engines, I’d be afraid of the additives that are in modern oils.
 
Commercial guys running old two-stroke Detroits used to do that sometimes, believing with some justification that a Detroit will run on almost anything flammable. Modern diesels with electronic fuel controls might hiccup, though.
 
I am another that is tempted to try it. I would expect smoke similar to burning oil when valve stems or rings bypass it.
Yes on maybe the filters will get pluged faster, but then what was the oil filter doing?

For the test, if I dare, add to full tank or nearly empty is th equestion
 
SteveK said:
I am another that is tempted to try it. I would expect smoke similar to burning oil when valve stems or rings bypass it.
Yes on maybe the filters will get pluged faster, but then what was the oil filter doing?

For the test, if I dare, add to full tank or nearly empty is th equestion
Click to expand...

My thought would be to add to a nearly empty tank then top off. If I do it that way I won't be reporting on it for a couple years as I just topped off the tanks. This was very painful at today's prices. $5.19 a gallon including CA tax at the cheapest place around. That was double the cost of my last fill up two years ago. I think I might add some waste oil to my nearly full tanks to see what happens. I'm not due for oil change for quite some time as I did not put very many hours on the boat last year.
 
I would be concerned about some of the carbon in the used oil making it past your fuel filters and damaging your injector pump over time. The damage to the injector pump would out weight the cost savings in diesel fuel.
 
Several years ago, we would run the used oil thru the diesels, but with the modern high pressure common rail engines with the fine tip injectors I would be hesitant to do it.
 
Greetings,
The first thing that comes to MY mind is why? You'll be saving less that $100 and adding unknowns to fuel that you've already paid too much for. With all the threads on filtering and keeping fuel clean and dry it's just not worth the bother IMO.
 
What are you potentially saving vs the potential problems? I am not sure but my engines are way too expensive to chance it to save a couple of dollars.
 
I would be reluctant to burn waste oil even in an older vintage engine.
Remember that we change out that oil to get rid of contaminants and corrosives.
Also, the particulates will clog your fuel filters that much sooner, adding that cost.

SteveK, to the best of my knowledge, fuel filters are rather less microns than oil filters.
 
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I've been burning waste oil added to a diesel tank for over 60 years w/o problems. My fuel filters were enough. No running or starting problems.
 
I used to add all of my waste oil to the fuel of my ‘86 Hatteras with 671 detroits. Never had a problem with less than 5% oil.

I have a ‘94 ford f250 with the 7.3 idi that I run 85% used motor oil with 15% unleaded gas filtered to 0.5 microns. So far I’m up to about 70k miles with no problems. At fifteen cents per gallon and about 9mpg so far I’ve saved between $25 and $30k in fuel savings. Not bad for a $6000 truck. Can’t decide if I should buy a new truck or just wash that one.
 
No one said anything about saving money on fuel, at least I didn't. If that was the goal I would have already done it. This is about an easy waste oil disposal, that is all.
 
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SteveK said:
No one said anything about saving money on fuel, at least I didn't. If that was the goal I would have already done it. This is about an easy recycling, that is all.
Click to expand...
Burning waste oil should not be confused with recycling waste oil.
Rather, burning is one form of waste oil disposal.
Recycling waste oil involves separating the oil from impurities and re-refining it.
Then it gets turned into new lubricants, fuels or other petroleum products.
 
KnotYet said:
Burning waste oil should not be confused with recycling waste oil.
Rather, burning is one form of waste oil disposal.
Recycling waste oil involves separating the oil from impurities and re-refining it.
Then it gets turned into new lubricants, fuels or other petroleum products.
Click to expand...

Thanks for the pointer, edited my post
 
I guess that it depends on the engine. With modern highly electronic controlled engines I would not risk it. With dinosaurs engine like mine maybe.
My engine is based on hercules diesel engine made to run on everything military could find to put in the tank so I would not worry much. I found people running it with tranny oil, engine oil etc.
However one thing I would consider is environmental impact. This is not because I can burn anything that I would do it. Burning engine oil would be the most dirty recycling option.
I could burn my trash in my garden instead of having them collected but I am not doing it...

L
 
Much of the recycled oil in my area goes to guys that are burning it for heating buildings, not for reconditioning.
We use to dump the waste oil into the fishing boats. Most had Detroit's
 
We have DD 6-71 and I think they will burn anything from #1 kerosene to #3 locomotive fuel oil. But I am not going to :)
 
That seems like a good strategy for crossing oceans (assuming you'd cleared it with the engine mfg). 200 hour interval is every 8 days running 24/7; that turns into a lot of waste oil. We change once per season - I suspect our Lehmans would run fine on 5% waste oil but not worth any risk in our use case.
 
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socalrider said:
That seems like a good strategy for crossing oceans (assuming you'd cleared it with the engine mfg). 200 hour interval is every 8 days running 24/7; that turns into a lot of waste oil. We change once per season - I suspect our Lehmans would run fine on 5% waste oil but not worth any risk in our use case.
Click to expand...

That would assume the engine mfg. has actually tested for this. Otherwise the person you talk to may make a personal opinion.
 
I believe old FF for those that remember him used to tell stories of burning waste oil from oil changes.

A search may dig up some of those stories/advice, maybe not, but like any fuel... if cleaned by proper filters, the right viscosity and in this case a huge dilution.... most engines may never know it.

A great way to dispose of changed engine oil when away from home port....sort of.

We used to burn it to hear our boat repair shop in an approved heating system, so at some point burning it meets probably a lot of state regs. Not sure what current Fed and state regs say.
 
RT Firefly said:
Greetings,
The first thing that comes to MY mind is why? You'll be saving less that $100 and adding unknowns to fuel that you've already paid too much for. With all the threads on filtering and keeping fuel clean and dry it's just not worth the bother IMO.
Click to expand...

That was exactly my initial thought as well RT, you beat me to it. Why in the world would you want to try this??? Risk contaminating your fuel tanks to save ~$25?
 
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I always have used the Racor fuel filters as a visual forensic clue as to fuel tank health. For that one reason alone adding a known dirty sludged up product to confuse things isn’t my thing.

For those who aren’t concerned about “perfect” fuel specs, high pressure modern injectors, tank sludge nor filter loading clues I can see the attraction.

Here is a test: take a clean white coffee filter and pour a cup or two of diesel, then used oil, and lastly a 1-2% blend through each filter.

As always, your boat and your choices as to how you choose to care for it.
 
My Marina used to have an oil recycling center. Dump used oil and filters. They took it out recently so now what to do? I could risk contaminating my beautiful car and drive to an Autozone or O'Reilly but they only want to take oil they sold you. So burning came to mind. Maybe I'll try it on my 32 year old Cat 3208s but I wouldn't try it on a common rail. Maybe I'll do one engine per fill up. Naw, that's a PITA.
 
RickyD said:
My Marina used to have an oil recycling center. Dump used oil and filters. They took it out recently so now what to do? I could risk contaminating my beautiful car and drive to an Autozone or O'Reilly but they only want to take oil they sold you. So burning came to mind. Maybe I'll try it on my 32 year old Cat 3208s but I wouldn't try it on a common rail. Maybe I'll do one engine per fill up. Naw, that's a PITA.
Click to expand...


I don't think auto parts stores are allowed to question the source of used oil. At least here in NY, they have to take anything you bring them, although they may be allowed to limit quantity per day.
 
RickyD said:
My Marina used to have an oil recycling center. Dump used oil and filters. They took it out recently so now what to do? I could risk contaminating my beautiful car and drive to an Autozone or O'Reilly but they only want to take oil they sold you. So burning came to mind. Maybe I'll try it on my 32 year old Cat 3208s but I wouldn't try it on a common rail. Maybe I'll do one engine per fill up. Naw, that's a PITA.
Click to expand...
Since you're in Long Beach, Al Larson's Boatyard nearby on Terminal Is. has a large
oil recycling storage drum.
It's pretty trivial to refill the empty oil containers and cap them. I always made the
biggest messes in the boat!
As long as you buy your oil in CA, the seller is required to accept your used oil, AFAIK.
 
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KnotYet said:
Since you're in Long Beach, Al Larson's Boatyard nearby on Terminal Is. has a large
oil recycling storage drum.
It's pretty trivial to refill the empty oil containers and cap them. I always made the
biggest messes in the boat!
As long as you buy your oil in CA, the seller is required to accept your used oil, AFAIK.
Click to expand...

I have never been over there except to get fuel at Jankovich. What is Al Larson's good for?
 
Used to be that most marinas and garages in the out islands had a 55gal drum filled with sand. They would pour used oil in the top and drain out pristine, ready to use oil out the bottom. Kinda scary if you ask me.
 
I’ve mentioned before that as I worked in a diesel-electric powerhouse in Alaska where the lube oil for generator engines was recycled w a big re-refiner that used high pressure and heat to process the used oil from oil changes. The biggest engine being a 1440hp Enterprise 16x20 in-line 8 cylinder engine.

The chief engineer said the re-refined oil was better than the new oil as one (or more) undesirable elements of the oil ( RPM Delo 30 weight ) is filtered out.

The dry sump engine had a 300 gallon oil tank so using new oil was quite expensive. All things needed to be barged or flown in… They used the oil several times at least.

This was at a placer platinum mine at a little town … platinum near Goodnews Bay in Bristol Bay … Western Alaska.

Re-refined oil was popular in auto parts stores in the 60’s and in the day I used it at times. All my cars then were old and worn out.
 
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