[Vwdiesel] Waste Vegetable Oil

Rolf Pechukas rbp at 4u2bu.org
Mon Apr 2 17:10:24 EDT 2007

> I have done some research on running waste vegetable oil &  
> apparently there are two schools of thought.  One is to start on  
> regular or biodiesel running the engine's heat thru a secondary  
> heater or heat exchanger in the WVO fuel tank. This requires two  
> separate fuel tanks. With this setup. With this setup, you must  
> switch back to regular diesel to purge the fuel lines & injector  
> pump of WVO, before shutting down. The other setup employs a  
> electrically heated fuel filter & heat tape along the fuel line  
> from the filter to the injection pump & from the IP to the  
> injectors. This permits running your car on only WVO.
> I would like to hear comments on how well the second option of  
> electrically heating the WVO works. From what I have read, the  
> Mercedes 300 diesels from 1979 to 1985 are the best for this second  
> type of option.

caution on running WVO
it is not as simple as one might think
there are a finite number of things that must be done right, but you  
have to do them all right or you may damage your IP, injectors, and/ 
or engine

there is no way to run 100% WVO heating electrically w/o purging  
this will not work

it IS possible to run a single-tank system - but this involves  
swapping out injectors and sometimes IP for special veggie-specific  
models, generally made by Ellsbett of Germany

it IS possible to use electric heat in conjunction with, or instead  
of, coolant heat, but that doesn't get you out of having to switch  
over to DSL fuel and purging

in single-tank (i.e. Ellsbett) conversions, WVO is generally blended  
in some percentage with DSL fuel

some people run a single-tank w/o modifying injectors or IP
they typically run a blend of WVO and DSL or WVO and RUG (Regular  
Unleaded Gasoline)

a lot of this depends on how warm it is where you live
in FLorida a lot of people run single-tank blends
in Minnesota almost no one does

earlier Mercedes ARE especially tolerant of WVO
this is because they have inline IPs
VWs are rotary, but they do pretty well also

the Lucas/CAV types are very fragile running WVO (Dodge? Ford? not  
too familiar w/ these)

but to run WVO successfully and long-term trouble-free in 90% of the  
US you'll want a 2-tank system
it is entirely possible to design and build your own conversion - you  
do not have to buy a kit
but you do have to know what you are trying to do

for example, heating just the VO tank is inadequate
in fact, you don't need much heat to the tank itself
just enough to keep it liquid
you need a little more heat to lines running from tank to eng bay,  
even more heat at the filter and before the IP, and, if possible,  
even more heat at the injector lines right before the injectors

this is not rocket science, but it is WVO conversion science
anyone dedicated to doing it properly with a decent set of skills and  
tools can do this, but expect it to take a while to get right (i.e. a  
year or so to work out every last little kink and get it running  
really right)

OR, you can just pour a little PROPERLY FILTERED AND DEWATERED WVO in  
with your DSL
but not more than 20%, and then only in the summer (unless you live  
somewhere hot)
5% max in the winter

my 2¢

peace out

Rolf in MA

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