How did the waste tranny oil/waste motor oil do as fuel? I am centrifuging a batch now.

 

This is a pretty old thread, but I keep tabs on posts on the subject of burning waste oils as fuel in diesel engines. Most people who burn WATF, as it is called, like it, and seem to have no trouble burning it. I have burned at 5 gallons of it, because I do not get that much, but it burned fine with no apparent issues.

WMO, on the other hand, in my 6.2L n/a diesel engine tends to coke my injectors. The people who seem to be able to burn it in a diesel engine with little to no trouble tend to have a turbo and centrifuge and filter their WMO, and it is generally blended with gasoline at 20% instead of diesel fuel as a thinning agent, and settled prior to centrifuge and filtering for at least 24 hours.

 

Thanks for your input. I centrifuge and blend with 20% flex fuel since it has ethanol and you recommended it for smoke abatement, I do. I had been using 10% unleaded, and was smoking white smoke to the point of fear of the man in the black and white car with red/blue lights. I also am centrifuging HOT (140-150F) and the current batch will have been centrifuged 4 times or more since I did not have time to settle it. Hoping for a smoke free ride, but waiting to mix for the tank till I get my viscosity cup. You inspired that piece of scientific evaluation.

 

Good to know that I have helped you some figure out how to burn waste oils. My guess is the reason why your first experiment smoked so bad was there was not enough gasoline in your waste oil blend to thin it out properly. My guess is if you had 20% it would have run fine.

On the flex fuel, I would not recommend it, only because the alcohol content can cause damage to silicon seals in your fuel system, if you have any. I know the 6.2 & 6.5 do, and the alcohol definitely will ruin that seal.

Also, I would not recommend heating then centrifuging any waste oil. It works better to blend your solvent, such as gasoline, with your waste oil first, because not only does the solvent thin the waste oil out so that it does not have to be heated to centrifuge it, but settling the waste oil-solvent blend for at least 24 hours after blending will remove most of the crude. All you have to do is separate out the sediments from the good thin fuel blend that floats on top, then centrifuge that. Typically the good fuel is the top 80%.

 

ON the flex fuel, please correct my error. I thought that you said ethanol was preferred to reduce smoking? flex fuel has an ethanol component, so that is what I used. Should I be getting regular unleaded and adding ethanol, or am I misunderstanding the ethanol issue?

 

I do not believe I ever said ethanol was a good thing to add to a diesel fuel blend. I was only stating that ethanol is a better anti-knock/octane enhancer for gasoline engines than the previous anti-knock/octane enhancer in use, because it is far less toxic, but that is for gasoline engines. It does not help diesel engines, because they do not need octane enhancers.

So, the best form of gasoline to blend in a waste oil-based diesel fuel would be a gasoline, or some other solvent, that does not have alcohol in it.

 

hey guys, I have been running used tranny oil for about the last month and a half now in my truck. I have a 91 f-350 with the idi in it. I run it over a large magnet, (the parts washing bowls with magnet are good and easy to use) and then through a centrifuge. I have found it will run at 100% tranny fluid fine, but it has some problems cold starting, that being said i need to replace most of the gp system and only have a few working. I usually mix 1.5 gallons of diesel per 20 gallon tank and that helps thin it out and start like regular diesel. Your biggest worry is the metal particles as even regular diesel has some pretty big chunks of crap in it. I have been running my centrifuge off an old power steering pump with the v belts powered by a grinder motor that I took off the grinder head and put a pully on. it runs between 70 and 80 psi. No problems yet related to the fuel, other problems with my truck have it grounded right now though...stupid springs in the flywheel are spitting out of it, and its just time for injectors to be replaced (was before i started running the tranny oil in it, part of why i tried.)


Also to thin it out use diesel, NOT GASOLINE. You should never run gas in your diesel because it will have ethanol in it no mater where you get it (mandated by federal law) and breaks down the lubrication in the oils, and prevents the cylinder walls from being properly lubricated. On top of that, contrary to popular belief, diesel has more power to the fuel than gas (higher octane rating) the confusion comes from the gas needing a much lower compression ratio to explode and will explode before the piston has completed its stroke causing damage to the engine. Even a little gas breaks down the lubrication across the whole tank. I know diesel is $0.40 per gallon more but you shouldn't need more than a couple gallons per tank, just use the diesel.

 

Thanks thatdude38, for filing your waste oil report. Most people can burn WATF with little trouble, and almost no solvent, so good to have your report. However, most of them will find that gasoline at 5% will improve combustion of their waste oil blend, so that their engine will start and run better on WATF, even on a cold day.

However, gasoline blending does not do any of the things that you are claiming.

Yes, most, if not all gasoline sold in the USA has been mandated to contain ethanol since 1996. Gasoline with or without ethanol in it will not do any of the things that you claim it does to a diesel engine. However, old diesel engines like yours and mine, have silicon seals in their rotary injector pumps, which swell if ethanol is in the blend in greater than 3%. ethanol is never in greater than 11% in gasoline, unless posted otherwise, such as e85. Most people who blend gasoline with waste oils never exceed 20%, which makes the ethanol content in the resulting blend lower around 2%, which is safe for silicon seals.

On your lubricity issue, yes gasoline in a waste oil blend reduces the blend's lubricity; however, when it comes to petroleum distillates, lubricity is a function of specific gravity & viscosity. A blend of gasoline with 10-40 motor oil, or canola oil with gasoline at 20% will have greater specific gravity & viscosity than diesel fuel; therefore that blend will have greater lubricity than diesel fuel. The same would be true for a blend of WATF and gasoline at 5%.

Yes, it is true that gasoline has lower energy content (BTUs) than diesel fuel has; however, waste oils have more energy content (BTUs) than diesel fuel has, so blending gasoline at even as high as 50% in most waste oils would produce a fuel blend that has the same energy content (BTUs) as diesel fuel has. Therefore, a waste oil blend with less than 50% gasoline will have more energy content (BTUs) than diesel fuel has.

I have been running a Chevy van with a 6.2L diesel engine in it on 80-20 WVO-gasoline blend since February 2007.