Want to use biodiesel in 1982 300D, W123

[David4]

What if modifications do I need to do in order to run biodiesel in my 1982 300D?

[bbail2x2]

I've been running B50 in a VW for 6 mo. and now an 85 300CD for about 3 months. both run well. As I understand it you may need to change fuel lines eventually but it is not immediate. my return lines on the VW got mushy so I replaced them with urethane lines. much cheaper than viton and BD compatible. you should check with a few BD sites because some folks here don't know about BD, they just pass on info that may be questionable. I hope someone else who has years of BD experience will add to this.

[zeke]

Do you mean bioD or veggie oil?

BioD no modification needed. Depending on whether you are going to run more than a 50% mix (B50), you may want to fade it in over a couple of tanks in case loose crud floats into your filters.

Veggie....well, do some searching around the forum and then decide for yourself whether it is worth it to start ANOTHER thread on the subject....

[John Schroader]

My $0.02 worth. You need no modifications at all. Have read that fuel lines may get mushy but my '83 has two years and 18K miles on bio (mostly 100%) with absolutely no problems. Also about same milage on 7.3 Ford with, again, no problems.

[bgkast]

Fill 'er up!

[Jeremy5848]

Biodiesel will soften/melt the rubber of the fuel filler neck seal, allowing rain into the trunk of the car. Replacement seals are no better. Put a rag or something around the neck while filling the tank. I cut a hole in a sheet of rubber gasket-like material and put it over the neck as a sort of "diaper." It rots from BD also but is easier/cheaper to replace.

The fuel lines in the engine compartment can be left until they start to melt, which may be years down the line. The little jumpers on the injectors seem to rot after about a year so I recommend replacing them with Viton. The short pieces of hose under the fuel tank need watching too; they are out of sight so most of us forget about them until they start to drip.

Biodiesel is an excellent solvent and may loosen any crud that has deposited out on the walls of the fuel tank and lines. Keep a close eye on the primary filter and change it if it shows any sign of clogging. Change the secondary more often too, perhaps as often as every few months, for the first year or so, until your system is thoroughly cleaned out. I did not have to do that but it is possible.

Parker makes a biodiesel-rated hose and most (gasser) fuel-injection hose has a center lining designed to hold pressure but also capable of withstanding biodiesel.

This forum is full of threads on this subject that will keep you busy reading for hours. The search function will find them for you.

Jeremy

[David4]

Wo! I didn't realize biodiesel and vegetable oil were two different things. I guess I need to do some reading. I did mean I want to use vegetable oil though.

[zeke]

My advice, do alot more reading here and elsewhere...then put on your best flame suit before you post!

Yes, people often get the two confused. Vegetable oil is definitely not BioDiesel.

[JEBalles]

I recently took a three day course at a design school in Vermont to convert my car (1983 240D) on vegetable oil. It's not terribly complicated, it's just a matter of using waste heat from the engine to heat and lower the viscosity of the vegetable oil so it can make it through the injectors and burn in the engine. It's just a matter of rerouting your fuel and coolant lines with the addition of two valves and a tank in the trunk. A kit for yourself costs about $1000 from greasecar.com, but you can get all the materials for about $400, it just means you'll have to fashion a lot by yourself, not for the beginner. You also have to be willing to drill holes in your frame. After the conversion, you'll also end up cranking a lot of air through the system, but that goes away once everything starts running. After that, all you have to do, if your using waste oil, is run it through a filter bag to take out particulates and make sure there's no water and your ready to go. Virgin oil goes right it. You also have to run the engine on diesel until the engine reaches operating temperatures (~80 C for mine) to switch and you must purge the system of vegetable oil before shutting off the engine if you want to start it up again. All that is just a matter of an electric switch.

Originally Posted by JEBalles

it's just a matter of using waste heat from the engine to heat and lower the viscosity of the vegetable oil so it can make it through the injectors and burn in the engine.

Its not just about the injectors, its the injection pump as well.