Thread: Two Tank setup
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Old 01-23-2018, 03:47 PM
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Join Date: Feb 2011
Location: Los Angeles
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Quote:
Originally Posted by hanky6000 View Post
I agree that these engines were designed for diesel. As someone said earlier, its a calculated risk. I've never seen my cars pre chambers or cylinders but I have seen the carbon that comes out of the glow plug holes after years of veggie oil! My gut feeling is my 616 just shouldn't see veggie oil until it is at full op temp in order to burn as cleanly as possible.

The thing that makes WVO worth it to me is saving money on fuel. I pick up vegetarian frying oil from two restaurants for free and filter that oil to 5 microns in my shed. I use this to get to work which is 20 miles each way. I also go on tons of regional and long distance trips on veggie oil. My guess is I've had about 60,000 miles worth of wvo run through my car.

In terms of investment and cost, this all came from a 8th grade research project I did and I said the first car I get will run on grease! I was naive but got into it and into filtering oil pretty well by the time I got the car at 16. I'm almost 28 now so I can't go back and say "was it worth it?" But I have the simple chores it takes to keep it going as part of my life. For better or worse lol.

My 83 240d auto is my first car and just keeps going. I treat it like a farm truck and in my teenage years, I was bad about maintenance. It's had some accidents and and the paint is kind of patchwork. It's also arguably the least desirable model being pretty slow (its fine for me except in the rocky mountains). Everything that has gone wrong I've learned lessons on how to prevent wvo related problems in the future (Injector clogging, glow plug failure, leaks etc..).

In the process of owning this car for so long, I've gotten good at wrenching and do 90% of work myself. Next week however (because i'm lazy and don't have a compressor) i'm going to pay a garage install some brand new heavier 300d turbo rear springs so I can hall more veggie oil and my canoe for a planned trip to the everglades!

This picture is from a sea kayaking/wvo trip to maine a 3 years ago. I've done a lot of welding since then! P.S. This should be obvious but don't ever tie a boat on your car like I did here. I ruined part of my door seals from this!
Vegetable oils are highly unsaturated and will undoubtedly polymerize over time. That being said, many of the failures I have observed over the years are, at least partially, self-inflicted. First, I have lost count of the number of W123's and W124's I have encountered with no thermostat. These engines are designed to operate at a specific temperature yet, I guess some reason, the colder the better. Second, glow plugs at startup help the fuel burn cleaner and more completely. This is particularly true of vegetable oil. How many of these cars are operated with one or more glow plugs out? Those cylinders will not burn properly on startup. On the subject of glow plugs, there are several method of providing for "afterglow" or keeping glow plugs on for a short time after startup until the engine is up to temperature. This will allow time for rings to properly seat and reduce engine oil dilution. Third, changing the engine oil much more frequently, perhaps every 3000 miles maximum. Prior to changing, do an engine oil flush with something like Motor Medic MDF1 which is specifically designed for turbo diesels. With every oil change, also change the fuel filters and fill the new filter with Diesel Purge to clean the injectors. Fourth, don't heat the tank and don't allow the return line to heat the tank on long trips. Loop the return with a three way valve with one direction being "loop" and the other return to tank but use only to flush any air out of the lines. Polymerization rates double with every 10 deg C and keep in mind, almost all polymerization starts in the tank from the constant fill/drain cycles sweeping the walls of the tank.(polymerization is a thin film phenomenon, oil against reactive metal exposed to oxygen) So the colder the better if you don't need heat to keep the fuel flowing. When summer comes, shut off the heat.
It is possible to successfully operate vegetable oil in these old diesels for well over 100K miles, but it's not easy and does require constant attention.

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