This question deals with using used vegetable oil as a substitute for
diesel fuel. A two tank system that heats the oil is used in some
cases because the oil is too viscus when cool. It seems that no other
additives are needed. I figured I could just dilute the oil with gas
to change the viscosity and am trying it. I'm using a mix of 4 parts
uvo to 1 part gas and nothing else. I'm on the second 20 gallon batch
and it seems like it runs just fine. It starts with difficulty when
cold but it starts. Not being an expert I figure I'm pretty close but
need a pro to tweek the formula to make it more efficient. Also would
additives help and am I maybe doing something that will hurt the
engine? I'm running a 6.2 liter GM diesel engine.

They used to put sugar in gas tanks to sabotage military vechicles.

Be sure the deep fat fryers you get the oil from don't leave salt or
sugar in the fryers.

The Wall Street Journal ocasionally has quotes on edible tallow and
unbleached greases.  Be sure your getting and giving a reasonable
value.

Hello jerry_2-ga

I'm not an expert on fuel, but I have a 'nodding acquaintance' with
what you are trying to do.

A couple of points to consider before I continue.

1.) What you are doing might actually be illegal if the fuel mix does
not meet EPA standards.

2.) Be cautious as to the effect the fuel may have on filters in your
engine, also be aware that 'fatty deposits' might accumulate in the
fuel lines.

OK.  There is a company in Malta that does exactly what you are trying
to do.  Below you will see an excerpt from their website along with
contact details.  I would suggest you get in contact with them and get
their advice.

"The waste cooking oil is processed and converted into biodiesel a
fuel which is the name of a clean burning alternative fuel, produced
from renewable resources. It can be blended with any level of
petroleum diesel to create a biodiesel blend. It is biodegradable,
nontoxic and essentially free of sulphur and aromatics. Biodiesel is
better for the environment because it is made from renewable resources
and have lower emissions compared to petroleum diesel.
In most cases, even in Malta, biodiesel is mixed with conventional
diesel. Common blends are B20 and B2. The Environmental Benefits of
using biodiesel scales with the percentage of biodiesel contained in
the blend."

"WasteServ Malta
Phoenix Building
Old Railway Track
Santa Venera

Tel: (00 356)2385 8000
Freephone: 8 00 7 22 00
Fax: 21 441930
email: info@wasteservmalta.com"

http://www.wasteservmalta.com/page.jsp?id=601&mainid=21&siteid=1

Also, another great resource that you will find useful is:
"Make your own biodiesel"
http://journeytoforever.org/biodiesel_make.html

And on this page you will find some recipes:
http://journeytoforever.org/biodiesel_link.html#homebrews

Does that help any?

Very best regards

THX1138

While it's impossible to determie whether you are hurting your engine
without actually knowing exactly the kind of oil you're using and kind
of engine you have, there's some ways to make sure that you don't hurt
your engine.

If you have money to spare, and really want to focust on converting to
veg oil, go here: http://www.greasecar.com/
They sell a conversion system that will allow you to tun straight off
of vegetable oil. It has its own filter and what not, and you don't
have to add oil for viscosity. The downside is they're pretty
expensive... ~$1,000 each.

Of course, if you don't want to go for the extra cost,
http://www.ravenfamily.org/andyg/vegoil.htm has some nice advice.
*The seem to favor 50-50 blends.
*Discarded food oil is fine, but it would be a good idea to filter it
through a 25 micron filter (since anything that passes through that
will pass through your engine).
*Let oil settle a while to make stuff (water especially) sink and float before use.

Or if you're up to the challenge, make your own biodiesel
http://journeytoforever.org/biodiesel_make.html

Hope this helps.

Well jerry

what you have done will work but the engine in question has a problem,
you will be using the stanadyne or rotormaster injection pump. this
pump is of the rotary type and has a tolerance on the shaft of just 1
micron it will work but not for long! because veg oil is at least 6
times more viscous it will not lubricate the shaft properly and you
will end up snapping the shaft of your injection pump. adding gas into
the intake port will not help thin the oil as it is the injection pump
that requires the thined oil. using gas is a good idea with these and
other engines and used properly it will actualy increase the life of
the engine along with performance and economy gains.
to ensure you have a reliable engine you need to use a two tank system
on this engine a startup tank with diesel and another with veg oil and
separate fuel lines preferably with heated filters such as those found
on peogeot diesels (remove the thermostat) and certainly with some
form of heat exchanger to get the oil up to coolant temperature.
another rather cheaper and less technical solution would be to dilute
the vegoil with say 50% diesel which would help but i'm afraid you
will still encounter problems in the winter if you continue to do
this.