Diesel Fuel Blend

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Oct 6, 2007
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1983 42' Present Sundeck
Need some input.........
My dad has been going on and on about a process that uses waste oil and filters/ blends it with diesel fuel. This mixture is then used in diesel engines at a 50/50% or more blend. See www.myfastfuel.com. I promised him I would do some research on it. I talked with my diesel*fuel pump shop owner today and he told me the Ryder Truck shop in town use to clean/ mix their waste oil and pour it right back in the truck. Any negative results- I asked? Yes- he responded- we haven't had to make a fuel pump repair in years! What does the class think?* Any info on the glycerin that needs to be removed?
Steve-- I don't have any information for you, but this topic has come up many times and been discussed in great detail, pro and con, on the Trawler & Trawlering list (T&T). If you have not already done so, you might want to go to their archives http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering* *and search through the previous months by subject.

-- Edited by Marin at 22:51, 2008-01-30
My dad has been going on and on about a process that uses waste oil and filters/ blends it with diesel fuel.

Go to the Detroit Diesel site and they have photos of various damage caused by this insanity.

And the Watermelons (green outside, red inside) will have a hissy fit as the air pollution is poisonous from all the metals in the fuel.They can not be filtered out .

That's been done for years, but I've never heard of a 50/50 mix. More like 5% waste oil metered back into the fuel, after filtering.
I asked before (on the OTHER site) about the feasability of puting the oil from the oil change back into the fuel tank.* Can it be done -- and if so, what precautions should/must be taken?* Should it be done"?
With older mechanically injected engines (not common-rail), you can probably get away with it. Obviously, filtering is essential. I'm certain that I could pour a couple of gallons into each tank on my boat, and the "girls" (6.354 Perks) would take it in stride. Lehmans would probably be the same.

But it seems to fall in the category of "just because you can doesn't mean you should."

Six gallons or so of waste oil after a change might replace, what, 20 to 25 bucks of diesel?

Even if it's a really slim chance that it would goober up an injection pump or an injector, it just doesn't make sense to me.
Bio Diesel has up to 40% vegetable oil and has been sold/used in the State of Washington for 5+ years.* Most of the city busses and even the ferries run Bio Diesel. **I have run a couple tanks full of bio diesel and did not notice a difference in the pick up. For the last couple of *years I have been running ON road #1 or #2 ultra low sulfur diesels for the Webasto, which burns clean, there is no smoke/soot/smell. I also have run through the 671 and the gen. set, but added Marvel oil just to make sure.* *On the Marvel oil diesel additive it gives the ratio.* I think its like 1 quarter per 50 gallons.* Anyway I would not mix more than what Marvel Oil recommends.*

On long range boats they burn the old oil so it doesn not have to be stored,*but other than that*would NOT mix old oil into the diesel,when most marinas have a oil recycling tank.***************************
I guess I am thinking of other applications than the old bateau..... Possibly the shop forklift (old Allis Chalmers), maybe my '05 Ford 6.0. We generate 20 gallons+ a month (mostly LP fueled forklifts) of waste oil that is picked up and recycled. It seems a shame to have this hauled off it it could be used. I would like to see the DD info and pics. Can you pop a link FF?
Forklift yeah, late model Ford pickup, nyet. That's a modern common-rail engine.
I have searched the www.detroitdiesel.com website and cannot find any refrence to this. I am not saying that blending waste oil is safe to do. If anything - I am skeptical. I am a long way off from trying this. Maybe never will. At the same time I would like to reduce the damage to our Exxon Card bill and put a dent Exxon's profitability!
One of the things I would be concerned about in adding used oil to diesel fuel is--- in addition to the particulate contaminants--- the introduction of the acid that builds up in diesel lube oil as it is used from blowby gasses and whatnot. I know this acid can be damaging to things like bearings and bushings if it's left in an engine that isn't run for a long period, like a winter layup. Perhaps it would not have any damaging effects in fuel, but that's one of the things I'd want to find out about before I tried it.
I don't know if people are still reading this thread, but I'll give it a go.

There are basically a few different types of waste oil that could be used as fuel extender.
Used sump oil
Waste cooking oil
Used transmission oil.
Hydraulic fluid and A/T fluid

I would forget the last two because of the high content of additives in it.
Used sump oil. Most old timer truck drivers poor their sump oil back in the fuel tank. Yet this amounts to less than 10% mix. I wouldn't do it.
However there is a way to do it safely, and that is by getting the oil through a centrifuge first. Forget filtration, the best filters can at best stop 5 micron particles. a centrifuge gets rid of particles down to one micron and can be cleaned and up it goes again.
Considering that an Alfa Laval "Emmie" costs $30,000, this seems a lost cause, yet I found a cheap alternative http://www.simplecentrifuge.com

Centrifuge your used mineral oil, and mix at a guess not more than 30% depending on what engine you are using. Older engines take better to thicker fuel than new one.
On the subject of cheaper fuel, a centrifuge should also make it possible to use heavier diesel designed for bigger engines. The centrifuge will eliminate the particles of tar that would otherwise ruin your injectors and pump.

Waste vegetable oil or even new vegetable oil, is another matter.
You can run a diesel engine on straight vegetable oil if you take a series of precautions and convert your engine to use this fuel. It implies the use of a dual fuel system to start and stop the engine on mineral diesel and also a system to heat up the fuel. There is ample information on the net if you search "straight vegetable oil".
An alternative to SVO is the much tooted Bio-Diesel. It involves converting the vegetable oil into a fuel that has similar viscosity to Diesel and for that it is necessary to put the waste or new vegetable oil through a process that includes decanting, a chemical reaction with methanol and Potassium or Sodium hydroxide to eliminate glycerin, more decanting and last washing with water to extract the residue of the chemicals used.

Again there is a world of information about making biodiesel considering it is the fad of the moment. Thousands of people make their own fuel this way.
I decided against it because it would invalidate my home insurance, go against council regulations, I will have to pay exice to the tax man for the fuel I make and also I don't see myself collecting grease waste from my local fish and chip shop and wrestle 44 gallon drums home.

However some do it happily and here is a happy example of a farmer who makes fuel straight from the canola seed.

All in all, and considering I don't have a boat to speak of, I would forget SVO unless you have an old engine with a mechanical lineal pump and are happy to use just 10%. I would experiment with waste sump oil and a home made centrifuge. (I know of generating plants and larger boats who have a centrifuge incorporated in their fuel polishing system.)
Depending in which country you are and the differential prices and availability, heavier diesel fuel for larger ship may also be a consideration if previously cleaned from smaller particles and if in fact cheaper at all.

However all this is just my opinion not to be taken too seriously.
If the injectors are gunked Stanadine will cure it , if it can be chemically cured.

If you worry about the lack of lubricant in the latest Gov mandated fuel,
one gallon per 100 gal of any brand 2stroke outboard oil (100-1) mix will keep the engine and fuel system intact.


I have used the following mixture for my Toyota 4Runner diesel for the last 50,000km
Mix 600cc of <u>pure</u> acetone with 400cc of synthetic 2stroke oil to make one litre of additive.

Add 100cc of the mix to every 40 litres of fuel.
Sorry about the metric units, you can use a convertor here

I'm glad you brought up the Stanadyne product.* For 10 years the PO relied on a fuel polisher and oversized Racor filters*and refused to put any additives in the tanks of my boat.**That process*seemed to work but I got convinced to spend some of the boating budget on*the prescribed*quantity of Stanadyne and added it to both of the fuel tanks.* That was last fall.* *We're not living aboard yet so I didn't use the Hurricane diesel heater very much over the winter.* When I did light it off a few weeks ago*it ran for a bit and flamed out.* Investigation revealed the fuel pump diaphragm had melted.

I can't definitively point to the Stanadyne as the culprit but it is certainly suspect.*

I'm not trying to bash Stanadyne, just saying that products that are "good" for the engine may not be so good for other onboard users of diesel fuel.

Ed wrote:*........When I did light it off a few weeks ago it ran for a bit and flamed out. Investigation revealed the fuel pump diaphragm had melted.

I can't definitively point to the Stanadyne as the culprit but it is certainly suspect.

I'm not trying to bash Stanadyne, just saying that products that are "good" for the engine may not be so good for other onboard users of diesel fuel.

Ed, there is a very simple way to find out. Get a fuel pump diaphragm, and some of the suspect product and leave it to marinate for a week or a month and see what happens.


-- Edited by Marc1 at 21:49, 2008-03-21

That's good advice but I've replaced the fuel pump with a piston type rather than a diaphragm.**I understand*Hurricane has gone to a different type of pump although I don't know what they're using.

Talking about fuel, what sort of diesel fuel do you use?
Is it the same diesel fuel used in trucks or do you use heavier fuel oil?
In Australia we call hem
Diesel...the one for cars and trucks
MDO medium diesel oil
HFO Heavy Fuel oil

I think there are two or three more classifications

-- Edited by Marc1 at 07:47, 2008-04-01

-- Edited by Marc1 at 02:31, 2008-04-02
Designation here is #2 diesel.
Steve, when I was working we used to sell sugar cane harvesters to US Sugars, a huge company in Clewiston, FL, the had big fleets of farm equipment and used to mix their used engine oil with the diesel burned in the tractors. That was about 12 years ago I dont know if they still do it or at what ratio they were mixing the two. I'll see if I can find out what they are doing nowdays.
Camano 31
Thibodaux, Louisiana

-- Edited by Steve at 18:48, 2008-04-01
Marc 1
In Aus diesel is classed as ADO Automotive Diesel Oil this can be summer or winter blend depending on Sulphur content. Summer ADO is for the north.
MDO medium diesel oil
MFO and HFO are medium and Heavy fuel oils as used in large diesel engines and boilers such as ships and power plants.
I would have to go back and look at my spec sheets to give you Densities and SG s of each class.
The question is if anyone uses MDO in Australia or Diesel 3 or 4 in the US, in your marine engine, and if there is any cost savings.
I spoke to a friend at US Sugars about my earlier post he said the engines in the newer equipment can't handle the used engine oil / diesel mix.
Camano 31
Thibodaux, Louisiana
Boats can sometimes hold fuel for well oaver a year. Cars and trucks a lot less - sometimes only days or weeks at most. For long term storage that most of us do in our boats, i will stick with the best pump diesel, not even bio, I can get. Tom*
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