Thread: Two Tank setup
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Old 01-24-2018, 10:20 AM
JB3 JB3 is offline
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Quote:
Originally Posted by Grzpdlr View Post
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.

or just put in a second plastic tank, and run it hot.

Never had much in the way of polymerization issues in 40k on vo with a 3 tank arrangement I installed in my 300D. 2 plastic VO tanks.
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