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Straight Vegetable Oil (SVO) Conversion

Subtitled: Adventures of the "Fry Guys"

SVO - Straight Vegetable Oil. Clean Virgin Oil of the Wesson or Mazola variety
WVO - Waste Vegetable Oil. Same Stuff, but after the restaurant is done frying with it.

Once upon a time, and far far away,

Greg Yohn & Steve Spence (The "Fry Guys") started converting Greg's '85 VW Jetta to dual fuel use; Biodiesel/diesel & SVO. The process was and still is simple. Startup the car on diesel (or biodiesel), use the heat from the engines coolant to heat SVO, and when it gets up to temperature, switch over to SVO. When its time to shut down, flip back to diesel (biodiesel) to clean the injection system of SVO, which can coagulate or coke. They drew up the idea on paper, and after making several visits to the hardware store, built an ugly and sort of working system. It did run, but....

Skip ahead to the present. 

Greg and his '98 Jetta TDI SVO Selector Switch Completed under hood system

Completed trunk system Heat exchanger visible clean or used, it's all fuel

Greg's '98 VW Jetta TDI is running a professionally designed and installed system. Steve and Greg have been having fun making friends with the restaurant owners, collecting and filtering oil, showing off the system, and performing general evangelism. Winning converts, they now introduce.....

The "Fry Guys" WVO Conversion system. 

The following diagrams, pictures and text represent a state of the art dual fuel system. The stock tank for diesel or biodiesel, and a second heated tank for Waste Vegetable Oil.

process diagram 6 gallon conversion kit .5 micron filter bags Transfer pump kit

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Click pictures to enlarge.

Ron Morrison's "Fry Guys" powered Bus

This afternoon we took the bus & picked up about 40 gallons of used peanut cooking oil to use in my diesel engine, FREE.   We also went & picked up another 55 gallon drum. There is a Moose Lodge wanting me to pick theirs up, & also 50 gallons or so at the Eagle's Lodge. Maybe will go to Okeechobee to pick up some more next month. Sure is nice driving around on free fuel.

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Sunday Bill & I went to Ocala about 15 miles away.   It took about 10 miles of driving to get the waste oil warmed up to be used.   It sure is a nice feeling to be able to use free fuel.

The barrels on the back for for picking up oil. The taller of the 2 has about 40 gallons in it. I have available around 100 gallons to pick up, so I need to get some of the 40 gallons filtered. I have about 4 gallons of the 1st 25 gallons left to pour into the tank, plus about 8 gallons in the tank.    Ron

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#900 shows 12 gallon tank mounted under bus floor.   It is presently being
held up with 2 pipe straps, but within a week, I plan to have a 2X6 going the
opposite direction to have sturdier mounting.

#901, shows view from inside bus, showing hole cut in floor to fill tank &
see gauge.   Already plan to put the board back into it that I cut out.  
Unfortunately, I cit hole too big, listening to my friend as to the size hole I
needed.   Should have measured it myself.   Hopefully someday, I will have
another tank installed under the bus to hold clean fuel.    My mechanic friend
knows where there is an 120 gal tank he thinks would fit under the bus.  SO
MAYBE.   It would be nice to also have a dirty tank & to be able to pump dirty
oil into clean tank.    Bus has the power & space to be able to do it, so the
labor intensive work would be made simple.

#902 shows the complete setup on engine.   We had to replumb the diesel,
to go through the main filter & secondary filters before getting to the
solenoid switch.   The WVO comes from the 12 gal. tank into the Raycor filter &
then it meets the solenoid switch.   From there it goes to the lift pump & then
into the injector pump.  

#903 is just closer & shows Raycor filter down to the solenoid switch.  
Also shows the 2 heater hoses going to the WVO tank.

#904 shows 2 heater hoses in upper left coming from lower right in pipe
from thermostat housing, but now the mechanic says we should have hooked one of
the hoses into the water pump inlet, 

#905 for better use of heater for WVO tank.

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I've got 20 or 25 gallons filtered now.   It just looks like new Mazola
oil.  I started with a restaurant filter, which was given to me.   I bought 50
paper filters for $7.   Looks as if 15-20 gallons is all I'm going to get out
of the paper filters.   Then came up with idea to do pre-filter & .5 micron
filtering at the same time.   So I have a piece of white aluminum rolled & fit
inside a 8" funnel.   I put the bag inside & now have hung it on the restaurant
filter wire that holds the shape for the cone shaped paper filter.  
    Hope I am doing things ok.   Out of jugs to put oil in at the moment, but
still have 25 gallons or so of WVO.   Plus they said they'd have another 10
gal. for me by Monday. 

Before Conversion:

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How to Get Started:

1. Getting the Oil
First, find a restaurant. All restaurants use various forms of fry oil. Some restaurants use a hydrogenated oil that is solid at room temperature. This type of oil works fine once in your tank, but the transfer can be somewhat difficult. More often than not, restaurants use an oil that is still pourable at 35F. This type of oil is the best to use. It has been our experience that Chinese restaurants change their oil more often than other restaurants and therefore have plenty of it. The Chinese restaurant we get it from can supply us 50 gallons a week! Look around and find a restaurant with good oil, then talk with the owner. You may discover that when you tell him what you are doing, he'll be more than happy to give you the oil. However, you may find most large chain restaurants have an outlet for their oil. Smaller, independently owned places have problems disposing of it; they have to pay someone to haul it away. If you ask them for their used oil, we're sure they will be eager to give it to you.

2. Pre-filtering the Oil
The Racor filter that comes with the "Fry Guys" kit filters down to 28 microns. If the oil being used is dirty, the Racor will do its job and protect your pump and injectors, but it will fill up fairly quickly, and leave you on the side of the road cleaning your Racor, or burning regular diesel. (no, not that!) After collecting the oil, we filter it through .5 micron filter bags, then store it for use.

3. Maintenance
The only maintenance required is cleaning the Racor filter. The Racor filter element is a stainless steel mesh element and is easily cleaned. There is no expense after the initial investment.

4. Safety
Its as safe as using Wesson oil to fry dinner in. Vegetable oil is not volatile like gas and is extremely safe to store and transfer. It has a flash temperature of over 300F. The fuel tank is a marine grade tank that is inch thick polyethylene! Safe! Custom metal tanks are also available.

5. Warranty
There isn't a lot that can go wrong with the system, but if something does fail due to NORMAL USE, not abuse, we will work with you to get it repaired or replaced. However, because this is an install-it-yourself deal, we cannot be responsible for anything that may go wrong with your diesel motor. Rest assured, even with total negligence, a good heat lamp and a wrench will most likely fix things. There isn't much chance that it could really damage an engine. Each kit comes with detailed installation instructions, and tech support by phone or e-mail. We can also do the installations for you, and warrant our work. Here are some pictures of Toyota Injectors after about 8,000 miles on vegetable oil. They have not been cleaned at all, that is how they were when they were pulled out of the engine.

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6. Oil
Need oil? With some notice, we can supply 55 gallon drums of filtered oil, ready to use.

7. Power and mileage
Power and mpg numbers don't change significantly on vegetable oil.

Contact us at for a custom quote.

Authorized "Greasel" Distributer!

Green Trust
93 Sheldon Rd.
Winthrop, NY 13697