How To Run A Diesel Engine On Straight Vegetable Oil
Any Diesel engine can be modified to run on straight vegetable oil. This modification requires the addition of a solenoid operated fuel valve as described in ***, plus the installation of a custom-made metal fuel tank and modifications to the engine coolant hoses. These modifications are done in order to heat the vegetable oil so that it has a similar viscosity to diesel fuel. An engine modified to run on straight vegetable oil can still run on diesel fuel. This chapter contains technical instructions which assume the reader has an intermediate understanding of and skill with the Diesel engine.
HEATING THE VEGETABLE OIL
There are two reliable ways to fuel a Diesel engine with vegetable oil: make
the vegetable oil into biodiesel or heat the vegetable oil with engine coolant.
Since used cooking oil is solid at room temperature, it must be heated before
it can be used as a Diesel engine fuel. Hot vegetable oil flows easily through
Diesel engine fuel lines, fuel injector pumps, and fuel injectors. Injectors
can spray hot vegetable oil as well as they spray diesel fuel. If used with
caution, vegetable oil can be a reliable Diesel engine fuel.
The key to fueling
a Diesel engine with vegetable oil is to reduce the viscosity of the vegetable
oil. As the temperature of vegetable oil increases, its viscosity decreases.
Once the temperature of vegetable oil reaches 160° F
(70° C), its viscosity drops below 20 centistrokes. Although most Diesel
engine manufacturers specify a maximum fuel viscosity of 10 or 15 centistrokes,
most Diesel engines will run on vegetable oil with a viscosity of 20 centistrokes.
When vegetable oil reaches 175° F (80° C), its viscosity drops below
10 centistrokes, making it reliable for use in all Diesel engine fuel systems.
An engine running on vegetable oil which has been heated to 175° F (80° C)
will have similar injector coking and engine wear to an engine running on
petroleum diesel. In addition, an engine running on heated vegetable oil
will experience significantly lower emissions than an engine running on petroleum
diesel.
Although heating the vegetable oil is an effective method of reducing its
viscosity, this method has been ignored by most university and alternative
fuel researchers.
In the words of one researcher, the idea of heating the vegetable oil fuel
supply was dropped because "the entire distribution and storage system
would also require heating, a clearly impractical and expensive approach." While
this approach is not feasible in every situation. it is a very inexpensive
and practical means of reducing the viscosity of vegetable oil for use in
a Diesel engine.
STRAIGHT VEGETABLE OIL CONVERSIONS
The modifications necessary to run a Diesel engine on straight vegetable
oil have been duplicated by a number of companies and individuals in different
parts of the world. For example, in 1996, France's Center for International
Cooperation in Developing Agrotechnical Research ran a Renault station wagon
on rapeseed oil for 61,000 miles.' Other organizations who have successfully
modified Diesels to buts straight vegetable oil include Elsbett of Germany,
Better World Workshop of Vermont, and BioCar' of Germany.
The BioCar
Geor, Lohmann fuels his Diesel car with used vegetable oil straight from
restaurant fryer,. The BioCar- system designed and patented by Mr. Lohmann
has been installed in many direct and indirect injection Diesel vehicles
and Diesel generators. This system starts a Diesel engine on diesel or
biodiesel fuel, heats a tank of vegetable oil, heats the fuel line from
the vegetable oil tank to the injector pump, heats and filters the vegetable
oil right before the injector pump, and switches the fuel from diesel or
biodiesel fuel to vegetable oil. Mr. Lohmann sells a patented, high quality
BioCar" kit.
See the Resource Guide for information on contacting BioCar".
The Elsbett
Engine
The Elsbett engine is a type of Diesel engine made in Germany that runs on
straight vegetable oil. In 1992. Autocar and Motor Magazine published an
article on a Mercedes 190 which had been retrofitted with a 3-cylinder Elsbett
engine. In the article, Elsbett claimed that their Mercedes got 54 miles
per gallon in the city and 93 miles per gallon on the highway with a top
speed of 105 miles per hour. Although Elsbett engines appear to be superior
to the modern Diesel, Elsbett engines are handmade and cost at least twice
as much as other Diesel engines. For this reason, the Elsbett company has
recently turned its attention to modifying existing Diesel engines to run
on straight vegetable oil.
SAFETY PRECAUTIONS
Avoiding Injector Coking
Running a Diesel engine on straight vegetable oil can coke the injectors
and cause engine damage. Coking means that the tips of the injectors become
coated with a thick, hard layer of unburned fuel. After injector coking occurs,
the injectors w111 begin to spray incorrect quantities and patterns of fuel.
This can result in damage to cylinder walls and piston rings. Since most
of the coking occurs when an engine is started on cold vegetable oil. Diesel
engines running on straight vegetable oil must be started on diesel fuel
or biodiesel fuel, switched to hot vegetable oil for the majority of the
running time, and then idled for a short time on diesel or biodiesel fuel
before being shut off. Idling the engine on diesel or biodiesel before shutting
the engine off ensures that the fuel injector pump. the injectors, and all
of the fuel lines are clear of any vegetable oil.
Engine Coolant
Coolant is also called antifreeze. Usually, coolant is a mixture of 50% water
and 50%c green ethylene glycol-based solution. The purpose of coolant is
to keep the engine cool. It does this by circulating around the engine.
The heat from the engine is transferred to the coolant. The hot coolant
then flows through a radiator which uses a network of thin metal pipes
to transfer the heat into the surrounding air. This cools the coolant which
exits the radiator and goes back around the engine.
Engine coolant heats to at least 160° F (70° C) when the engine is running. Allow a Diesel engine at least 3 hours to cool down after running before disassembling, cutting, or otherwise modifying engine coolant and heater hoses. Preferably. all work done on the coolant system should be done in the morning after the engine has been turned off all night. Never open the radiator cap of an engine which is warm.
The ethylene glycol in coolant tastes sweet to animals such as cats and dogs. If a sufficient quantity of coolant is swallowed, it can be fatal. Do not allow coolant to drain onto cement where it can form puddles. Always store coolant in sealed containers. Always put engine coolant back into the coolant system.
Installing An Extra Fuel Tank
A few people have written to us concerning the safety of an extra fuel tank.
We do not recommend the installation of an extra gasoline tank. Gasoline
is very explosive. However, vegetable oil is not explosive. Installing
a tank to hold vegetable oil is not dangerous. The installation of a vegetable
oil tank into a vehicle is as safe as transporting vegetable oil from a
supermarket.
PARTS FOR MODIFYING A DIESEL TO RUN ON STRAIGHT VEGETABLE OIL
The 3-Port Solenoid Valve
Either the 3-port or the 6-port solenoid operated fuel valve made by the
Pollak Corporation and sold by JC Whitney can be used for this modification.
At the time of writing, the 3-port valve and the 6-port valve are the same.
The only difference between the units is that the 3-port valve comes with
3 of the 6 nozzles capped with rubber caps. To use the 6-port valve for this
modification, block off or ignore the 3 smaller fuel nozzles. The 3-port
valve will switch the source of fuel from the diesel fuel tank to the vegetable
oil tank but it will not
switch fuel return lines. The straight vegetable oil modification eliminates
the need for fuel return lines.
The Fuel Return Loop
Instead of returning fuel to the diesel tank as a normal Diesel vehicle would.
the modified Diesel engine will pump fuel from the return side of the injector
pump into the feed side of the injector pump. The return fuel line will
be cut 2 feet (60 cm) after it leaves the injector pump. After the fuel
return line is cut, it will be looped around and connected to the feed
line on the injector pump with a tee connector. The injector pump will
then pump fuel through the return line, into the feed line, and back into
the pump. There will be a circulation of fuel from the injector pump, to
the return line, to the feed line, to the injector pump. Meanwhile, more
fuel will flow into the feed line. Re-routing the fuel return line into
the injector pump eliminates the need to heat a fuel return line to the
vegetable oil tank.
The Custom-Made Heated Tank
In order to run a Diesel engine on straight vegetable oil, it is necessary
to build a heated, metal fuel tank. It is possible to build the fuel tank
from sheet metal, however, aluminum is preferable because it does not rust.
The aluminum tank will he installed in the vehicle and used as a second
fuel tank. When the bottom and sides of the aluminum tank have been assembled,
a loop of copper pipe is laid in a zig-zag pattern along the bottom of
the tank. Two holes are drilled in the bottom of the front wall of the
tank. This is the tank wall which will face the front of the car. The ends
of the copper pipe are then inserted into the holes so that the ends protrude
through the wall of the tank. The ends of the copper pipe are soldered
to the aluminum tank.
A fuel pickup pipe will bring vegetable oil from the bottom of the tank near the copper pipe up to the feed nozzle on top of the tank. The fuel pickup pipe and feed nozzle will be welded or bolted into the top of the tank. An extra option that the tank builder can install in the top of the tank is a fuel tank sender unit and float. The sender unit and float can be wired to the fuel gauge in the dashboard of the vehicle. The last step of the fuel tank building process involves welding the top of the tank, fuel pickup pipe, and feed nozzle to the aluminum tank. The aluminum tank looks like a normal fuel tank when it is finished, except for the two short pieces of copper pipe protruding through the bottom of the front wall of the tank.
The ends of the copper pipe that is inside the tank will be connected to coolant hoses from the Diesel engine. Coolant from the engine flows through the copper pipe inside the tank. As the engine and coolant heat up, the copper pipe inside the vegetable oil tank also heats up. The hot copper pipe heats the vegetable oil inside the tank.
The vegetable oil tank must have regular automotive fuel cap. This is the cap that you unscrew before filling a car with fuel at a service station. This cap has a small vent in it that allows air to slowly enter the tank as fuel is consumed by the engine. If the vegetable oil tank has a tight sealing cap instead of an automotive fuel cap, the tank could collapse in upon itself.
The vegetable oil tank can be built and installed by a professional fuel tank builder. Fuel tank building is done by some radiator repair shops, some boat builders, some automotive racing shops, and some off-road outfitters. To find an aluminum fuel tank builder, look in off-roading magazine ads and call boat builders and radiator shops.
The Hose Within a Hose
The hose within a hose is a length of translucent polyethylene hose inside
a larger diameter black hi-temp heater hose. Vegetable oil flows in the
polyethylene hose and coolant flows in the heater hose. but the two liquids
never mix. The purpose of the hose within a hose is to heat the vegetable
oil from the vegetable oil tank to the engine compartment. Since the vegetable
oil is surrounded by hot coolant, the vegetable oil heats quickly and evenly.
The two ends of the hose within a hose are identical. One end of the hose within a hose is in the engine compartment near the solenoid valve. The other end of the hose within a hose is next to the vegetable oil tank. At each end of the hose within a hose, the vegetable oil line passes through an adapter which is attached to the coolant hose. An o-ring is slid down the vegetable oil line until it meets the adapter. A compression nut is then slid down the vegetable oil line and screwed onto the adapter. clamping the o-ring around the vegetable oil line and making a tight seal between the coolant hose and the vegetable oil line.
Before the vegetable oil line is inserted into the coolant hose, a tee connector is spliced into the hose near each end. At the end of the hose within a hose in the engine compartment, the tee connector connects to one of the car's two heater hoses. At the end of the hose within a hose next to the vegetable oil tank, the tee connector connects to one of the two ends of the copper heating pipe in the vegetable oil tank. A separate coolant hose is attached between the other end of the copper heating pipe and the other heater hose in the engine compartment.
Once the vegetable oil heating system is complete,
there will be a circulation of engine coolant from the heater hoses in the
engine compartment, through the hose within a hose, to the vegetable oil
tank, and back to the heater hoses. Coolant will flow through the system
in the following order:
1. From the hot engine
2. Through one of the car's heater hoses
3. Into the tee connector on the hose within a hose
4. Through the hose within a hose
5. Out of the tee connector on the other end of the hose within a hose
6. Into one end of the copper heating pipe in the vegetable oil tank
7. Out of the other end of the copper heating pipe in the vegetable oil tank
8. Into another coolant hose called the coolant return hose
9. Into the other heater hose in the engine compartment 10. Back into the
engine
The Vegetable Oil Filter
A Diesel engine will run on used cooking oil that is passed through a 40
micron filter. The used cooking oil does not need a filter pre-heater for
a 40 micron filter as long as it has been heated at the vegetable oil tank
and has been flowing in the hose within a hose. 40 micron filters are available
for engine oil, hydraulic oil, and farming equipment. The Racor LFS remote-mount
oil filter comes with a removable, washable 40 micron mesh screen which works
well.
Although a Diesel engine will run on vegetable oil which is passed through only a 40 micron filter, it is advisable to pass the vegetable oil though a 25. 15, or even 10 micron oil filter before the vegetable oil is injected into the engine. These smaller micron oil filters require that vegetable oil is heated with a fuel filter pre-heater.
The Fuel Filter Pre-Heater
There are a number of fuel filter pre-heaters which are designed to heat
diesel fuel right before it enters the fuel filter. These heaters can heat
vegetable oil enough to pass through a small micron fuel filter. Fuel filter
pre-heaters are either coolant operated or electric. In general, coolant
operated heaters will bring vegetable oil to a higher temperature than electric
heaters. Racor makes a coolant operated fuel heater as well as several electric
fuel heaters. Another brand of electric fuel heater is the Dieseltherm. Look
in the Resource Guide for Racor and Dieseltherm.
The Thermoswitch (Optional)
A thernoswritch is a temperature activated switch. A thermoswitch is also
called a thermostat switch. Most automobile radiators have a thermoswitch
mounted on them. When the radiator gets hot, the thermoswitch turns on
a fan to cool the radiator. Good thermoswitches are adjustable. Adjustable
thermoswitches are available at automotive parts stores and through JC
Whitney. The use of the thermoswitch is not for a radiator, but for the
vegetable oil tank.
The switching of the vegetable oil fuel system can be automated by adding a thermoswitch to the coolant hose near the vegetable oil tank. When the thermoswitch senses that the coolant is the temperature which you have selected, it will activate the solenoid valve which will switch the fuel from diesel fuel to vegetable oil. Even if a thermoswitch is installed, switching the automobile back to diesel fuel before shutting the engine off will still be done manually.
The thermoswitch can be installed inside one of the coolant hoses near the
vegetable oil tank. Adjusting the thermoswitch is done by measuring the temperature
in the vegetable oil tank with a thermometer and comparing it to the temperature
in the coolant hose. When the temperature in the vegetable oil tank is 160° F
(70° C), the thermoswitch should activate the solenoid operated valve.
PARTS LISTS
Following are the parts needed for the straight vegetable oil conversion.
O.D. means "outer diameter." I.D. means "inner diameter." These
parts are based on standard measurements. We include the metric conversion
for each of the sizes. These parts are available in the United States at
hardware stores and automotive parts stores. However, exact equivalents of
some hoses and fittings which are available in standard measurements in the
U.S. are not available in countries which use the metric system. If you live
outside the U.S., use similar metric sizes for the parts listed here.
Parts: Tank and Coolant Return Hose
1. A custom-made aluminum fuel tank with a loop of copper pipe installed
into the bottom of the tank. The tank must have a fuel pickup pipe, a fuel
nozzle. and a normal automotive filler cap.
2. Some brackets to secure the tank.
3. 20-30 feet (10 meters) of 5/8 inch (15.875 mm) I.D. hi-temp heater hose.
Buy this black, flexible hose at an automotive parts store. We refer to this
as the coolant return hose.
4., Two 5/8 inch O.D. or 3/4 inch (19.05 mm) O.D. copper, aluminum, or
plastic tee connectors. The size of these tee connectors should correspond
to the size of the heater hoses in your vehicle.
5. Six 3/4 inch hose clamps.
6. Masking tape.
7. A permanent marker.
Parts: Solenoid Valve, Thermoswitch, and Filter
1. A 6-port solenoid operated valve with the 3. smallest of the 6 nozzles
plugged or ignored.
2. 6 feet (2 meters) of 3/4 inch (9.525 mm) I.D. black automotive fuel hose.
3. One 3/8 inch O.D. plastic fuel line tee connector.
4. Six 3/4 inch hose clamps.
5. A small amount of red, white, and blue enamel paint.
6. 10-20 feet (3-6 meters) of 18 gauge electrical wire.
7. One 10 amp automobile fuse and fuse holder.
8. An adjustable thermoswitch.
9. Oil filter of your choice. such as the Racor LFS with the 40 or 28 micron
screen filter or a smaller micron filter and a fuel filter pre-heater.
Parts:
Hose Within a Hose
There are many ways to make a hose within a hose. The parts listed here are
the correct size to connect to the Pollak brand solenoid valve.
1. 20-30 feet of 5/8 inches I.D. hi-temp heater hose. We refer to this as
the coolant hose.
2. 20-30 feet of 3/4 inches I.D. 1/2 inch (12.7 mm) O.D. polyethylene hose.
This is a translucent piping which is often used for fountain drink machines
and ice makers. We refer to this as the vegetable oil line.
3. Two 5/8 inch or 3/4 inch plastic, copper, or aluminum tee connectors for
the coolant hose. The tee connectors can be slightly larger than the inner
diameter of the coolant hose to create a tight fit.
4. Two 1/2 inch o-rings. The o-rings must be the same diameter as the outer
diameter of the vegetable oil line.
5. Two 1/2 inch compression nuts. The threads on these nuts are actually
5/8 inches in diameter, but the nuts are made to slide onto a 1/2 inch diameter
pipe.
6. Two 1/2 inch male threaded to 3/4 inch coarse female threaded adapters.
7. Two 3/4 inch coarse male threaded to 5/8 inch hose nipple adapters. The
hose nipples on these adapters go into the coolant hose. The male threaded
ends of these 3/4 inch adapters screw into the female threaded ends of the
1/2 inch male threaded fittings. You can eliminate these adapters if you
can find 1/2 inch male threaded to 1/2 inch hose nipple adapters.
8. Eight 3/4 inch hose clamps.
PREPARATION AND ASSEMBLY PROCEDURES
Preparation: Custom-Made Heated Tank
1. Determine the location where the aluminum tank will be installed. Possible
locations include: in the trunk, under a bench seat inside the vehicle,
in the spare tire compartment, under the dashboard on the passenger's side
of the vehicle, under the vehicle near the main fuel tank, or in the bed
of a pickup truck.
2. Measure the space where the fuel tank is to he mounted. If the tank is
to have a custom shape, draw the shape and measure all dimensions.
3. Using the dimensions you noted in step 2. make a mock tank out of cardboard.
4. Fit the cardboard tank into the space where the real tank will be installed
and determine:
a. How the tank will be mounted to the frame of the vehicle. What special
hardware will be needed to mount the tank. What special flanges or brackets
(if any) will have to be welded to the tank.
b. Where the fuel line and coolant hoses will be routed.
c. Where on the tank the fuel line will connect to the tank.
d. Where the two coolant hoses will connect to the tank.
e. From where the tank will be filled. Possible locations for a fill opening
are in the side of the vehicle, in the trunk, or in the engine compartment.
f. The route of the filler pipe. This is the pipe that goes from the tank
to the fill opening.
g. Any modifications that will have to be done to the chassis of the vehicle
to accommodate the new tank.
5. Mark the locations on the mock tank where the fuel and coolant nozzles
and the filler pipe will be located. Also mark any bracket locations.
6. Take the mock tank to an aluminum shop or a fuel tank builder.
Assembly:
Hose Within a Hose
1. Measure the route from the vegetable oil tank to the heater hoses inside
the engine compartment. The heater hoses are the two hoses which come out
of the engine and go through the firewall to the vehicle heater. Use a piece
of string to get an accurate measurement.
2. Cut the coolant hose to the length measured in step 1. Leave 6-8 inches
(18 cm) extra.
3. Insert a tee connector 4 inches (10 cm) before each end of the coolant
hose. Secure the tee connectors with hose clamps.
4. Run the vegetable oil line inside the coolant hose. Leave about 10 inches
(25 cm) of extra polyethylene hose hanging out of each end of the coolant
hose. Cut the vegetable oil line.
5. Put a hose clamp loosely onto one end of the coolant hose.
6. Slide a 3/4 inch male threaded to 5/8 inch hose nipple adapter over the
vegetable oil line until it meets with the coolant hose.
7. Push the hose nipple adapter into the coolant hose and secure it with
a hose clamp.
8. Slide a 1/2 inch male threaded to 3/4 female coarse threaded adapter down
the vegetable oil line until it meets the 3/4 inch male threaded adapter.
9. Apply some thread seal tape to the 3/4 inch male threaded adapter.
10. Screw the two adapters together. Tighten them together with two wrenches.
11. Slide an o-ring down the vegetable oil line. Push the o-ring down until
it meets the male threaded compression fitting.
12. Slide a female threaded compression nut down the vegetable oil line.
Screw it onto the male threaded compression fitting. This should cinch the
o-ring around the polyethylene hose and create a watertight seal.
Follow steps 5-12 for completing the other end of the hose within a hose.
Illustrations:
3. The brass adapters slide onto the end of the polyethylene hose in this
order. Teflon thread seal tape should be placed around the male threaded
brass fittings prior to assembly. 4. These brass adapters will clamp the
o-ring around the polyethylene hose. When the compression adapters are screwed
together, they will form a tight seal between the coolant hose and the polyethylene
hose.
5. The o-ring will be clamped between the male and female compression
fittings.
6. The nipple adapter slides into the coolant hose and the o-ring
is forced around the polyethylene hose and pushed down against the male compression
fitting.
7. The female compassion fitting is screwed on.
8. The end of the
hose within a hose is complete except for hose clamps.
9. The hose within
a hose is preliminarily attached to the solenoid valve to check for proper
fit and spacing. The last step in assembling the ends of the hose within
a hose is to secure all of the adapters with hose clamps.
INSTALLATION PROCEDURES
The heater hoses take coolant to and from the vehicle heater. These hoses
pass through the firewall in the back of the engine compartment. One heater
hose takes hot coolant to the car's heater and the other heater hose brings
cooler coolant from the heater back to the engine. We refer these hoses as
the "hot" and "cold" heater hoses. These heater hoses
are usually either SIR inch or 'I a inch inner diameter. If you cannot tell
which hose is hot and which is cold or where the heater in your vehicle is.
get a good service manual with pictures.
Installation: Tank and Hoses
1. Route and secure the hose within a hose from the vegetable oil tank location
to the heater hoses in the engine compartment.
2. Cut a length of coolant hose to the same length as the hose within a hose.
This new hose will be the coolant return hose from the vegetable oil tank
back to the engine compartment.
3. Route and secure the coolant return hose along the same path as the hose
within a hose.
4. Install the vegetable oil tank.
5. Attach the vegetable oil line of the hose within a hose to the fuel nozzle
on the vegetable oil tank.
6. Attach the coolant return hose to one of the copper pipes on the bottom
of the vegetable oil tank. Secure the hose with a hose clamp.
7. Measure the distance between the tee connector near the end of the hose
within a hose at the vegetable oil tank and the unused copper pipe on the
bottom of the tank.
8. Cut a small length of coolant hose and attach it between the tee connector
near the end of the hose within a hose and the unused copper pipe on the
vegetable oil tank. Secure each end with a hose clamp.
Installation: Hoses in the Engine Compartment
1. Determine the location of the two heater hoses in the engine compartment.
2. Determine which heater hose is cold and which is hot. Sometimes it is
necessary to turn on the vehicle and the heater and feel the heater hoses
to determine which becomes hotter. The hotter of the two hoses will be the
hot hose. The cooler hose will be the cold hose.
3. Put a piece of masking tape on each hose and label them "hot" and "cold."
4. Follow the directions in your vehicle's service manual to drain the coolant
system. Save the coolant in a sealed container.
5. Cut the cold heater hose in the engine compartment at the point where
you would like to attach the coolant return hose from the vegetable oil tank.
6. Put a hose clamp on each end of the cold heater hose you cut.
7. Insert a tee connector into the cold heater hose and tighten the hose
clamps.
8. Attach the coolant return hose to the tee connector and secure it with
a hose clamp.
9. Cut the hot heater hose at the point where you would like to attach the
hose within a hose.
10. Put a hose clamp on each end of the hot heater hose you cut.
11. Insert a tee connector into the hot heater hose and tighten the hose
clamps.
12. Cut a small length of coolant hose.
13. Attach one end of the small length of coolant hose to the tee connector
in the hot heater hose. Secure it with a hose clamp.
14. Attach the other end of the small length of coolant hose to the tee connector
near the end of the hose within a hose. Secure it with a hose clamp.
Installation: Refill Coolant and Check for Leaks
Now you have attached all of the coolant hoses and the tank end of the vegetable
oil line. The engine end of the vegetable oil line is still unattached.
1. Open the plastic coolant overflow container and pour the coolant you
drained from the system back in. Close the cap, start the engine and check
for leaks.
2. Let the vehicle idle and warm up and see if the vegetable oil tank gets
warm.
3. Check the coolant level after the car has run for some time. If the level
is low, add distilled water to the plastic coolant overflow container. Do
not open the radiator cap under any circumstances.
Installation: The Solenoid Operated Valve
The solenoid operated valve has 6 nozzles and 5 wires. We are only concerned
with the 3 large nozzles and the two wires which lead to the toggle switch.
1. Remove the solenoid valve from its box and inspect it. There should be
one large nozzle on one side of the solenoid valve and two large nozzles
on the other side.
2. Blow through the two large nozzles on one side to determine which one
is open.
3. Mark open nozzle with some red paint. The red nozzle designates the default
fuel flow path when the solenoid valve is turned off.
4. Mark the blocked nozzle with white paint. The white nozzle must attach
to the vegetable oil line.
5. Mark the nozzle on the other side of the solenoid valve with blue paint.
The blue nozzle connects to the fuel pump feed line.
6. Attach the solenoid valve to the sheet metal on the side of the engine
compartment. You may have to drill holes and use sheet metal screws.
7. Attach the vegetable oil line from the hose within a hose to the white
nozzle on the solenoid valve.
8. Follow the directions that come with your oil filter. Install the filter
into the vegetable oil line directly before the solenoid valve.
9. Remove the hard piece of fuel line which goes between the fuel filter
and the injector pump.
10. Use a hose clamp to attach a new piece of fuel hose to the fuel filter.
11. Attach the other end of the new piece of fuel hose to the red nozzle
on the solenoid valve.
12. Use a hose clamp to attach a new piece of fuel hose to the injector pump.
13. Attach the other end of the hose from step 11 to the blue nozzle on the
solenoid valve.
14. Check your work so far. Three should be a fuel hose from the fuel filter
to the large red nozzle on the solenoid valve. There should he another fuel
hose from the injector pump to the large blue nozzle on the solenoid valve.
The vegetable oil line from the hose within a hose should be connected to
the large white nozzle on the solenoid valve.
15. There is another fuel line on the injector pump which we have not touched.
This fuel line is the return line to the diesel fuel tank. Pull this line
off of the injector pump.
16. Plug the end of the line with a screw and a hose clamp.
17. Wrap the fuel return line up into a coil and secure it out of the way.
Label it "diesel tank return line." You will not use this line
again.
18. Use a hose clamp to attach a 24 inch (60 cm) long piece of fuel line
to the injector pump. This is the new fuel return line.
19. Cut the fuel line leading from the blue nozzle on the solenoid valve
to the injector pump about 3 inches (8 cm) before the injector pump.
20. Insert a small plastic tee connector into the fuel line you just cut.
Attach a hose clamp to each side of the tee connector.
21. Making sure that the fuel return line does not bend sharply or kink,
bring the new fuel return line from the fuel injector pump to the tee connector.
Make a mark on the new fuel return line where it meets the tee connector.
22. Cut the excess hose off the fuel return line and attach it to the tee
connector with a hose clamp.
Installation: The Toggle Switch
A toggle switch is included in the box with the solenoid valve. This toggle
switch is a double pole. double throw (DPDT) switch. Only a DPDT switch
will work with the solenoid valve.
1. Mount the toggle switch inside the
vehicle within easy reach of the driver.
2. Follow the wiring instructions
included with the toggle switch and the solenoid valve. Although the solenoid
valve has 5 wires, only 2 wires are necessary to operate the valve. These
2 wires lead to the toggle swwitch. 2 other wires lead from the car's battery
to the toggle switch. When the toggle switch is in the "on" position,
it connects the positive and negative wires from the battery with the two
wires from the solenoid valve.
3. Install an automotive fuse and holder near the solenoid valve on the positive
wire. If you are not familiar with automotive electronics, find a qualified
mechanic or electrician to install the toggle switch and connect power to
the battery.
4. Check your work. Leave the toggle switch in the "off' position and
disconnect the wires to the solenoid valve.
5. Start the engine and let it idle.
6. Touch the wires from the toggle switch to the solenoid valve. Did the
solenoid valve make a "clunk" sound?
a. If no, go to step 7.
b. If yes. or if sparks occurred or the car stopped, go back and recheck
the wiring.
7. Turn the car off and re-attach the wires from the toggle switch to the
solenoid valve.
8. Try the experiment again. Do not proceed until the touching of the wires
has no effect on the solenoid valve.
In order to prime the injector pump, fuel must be manually pumped through
the fuel line to the injector pump.
Installation: Priming the Injector
Pump
Most Diesel fuel injector pumps are not selfpriming. When a pump is
self-priming, it will pump air until it pulls liquid through. But a fuel
injector pump must have fuel from the tank, through the line, and into the
pump before it can pump the fuel. In order to prime the injector pump, fuel
must be manually pumped through the fuel line to the injector pump.
1. Detach the fuel line attached to the white nozzle on the solenoid valve.
This is the feed line from the vegetable oil tank.
2. To ensure that there are no blockages in the vegetable oil line, blow
air through it or shoot some compressed air through the hose. Remove the
fuel cap from the tank before you do this. You should be able to hear bubbles
in the vegetable oil tank.
3. Pull a vacuum on the vegetable oil line with a hand-operated suction pump,
a vacuum cleaner with a small sucker, or anything that pulls a vacuum.
4. - When vegetable oil flows freely from the vegetable oil line, re-attach
the line to the solenoid valve.
Installation: The Thermos witch
The adjustable thermoswitch sold by JC Whitney consists of an adjustable
switch with two wires and one sensor probe. The thermoswitch wires will
he connected in series in the positive wire between the toggle switch and
the solenoid valve. The sensor probe will be inserted into the coolant
return hose where it connects to the vegetable oil tank. When the coolant
which is returning from the vegetable oil tank to the engine gets hot enough,
the thermoswitch will activate the solenoid valve which switches the fuel
source to vegetable oil.
1. Disconnect the coolant return hose at the
vegetable oil tank. You may need to partially empty the coolant system
before doing this to avoid spilling coolant.
2. Insert the probe from the thermoswitch into the coolant hose.
3. Reconnect the coolant hose to the vegetable oil tank. Be careful not to
cut the probe wire. Secure the coolant hose firmly with a hose clamp.
4. Turn the toggle switch to the `oft' position.
5. Cut the positive wire between the toggle switch and the solenoid valve.
6. Use 18 gauge wire to extend each end of the newly cut wire to the location
of the thermoswitch. If the toggle switch is mounted on the dashboard but
the vegetable oil tank is in the trunk then you will need to make each wire
long enough to reach the thermoswitch.
7. Attach one thermoswitch wire to the positive wire from the toggle switch.
8. Attach the other thermoswitch wire to the positive wire from the solenoid
valve.
9. Adjust the thermoswitch so that it activates the solenoid valve when the
temperature of the vegetable oil in the tank reaches 160° F (70° C).
PUTTING IT ALL TOGETHER
Here is an example of how your modified Diesel car will run on straight vegetable
oil. It is a cold day. You get into your modified Diesel car and start the
engine. Since there is diesel fuel or biodiesel fuel in the main tank, your
Diesel engine starts normally. As you think about the 30 minute drive ahead
of you, you flip the toggle switch on your dashboard and arm the vegetable
oil system. Meanwhile, the vegetable oil in your second fuel tank is turning
from a solid block of lard into hot, flowing vegetable oil. In the few minutes
that it takes to drive out of your neighborhood, hot engine coolant is circulating
in the pipe inside the vegetable oil tank, heating the vegetable oil.
When the thermoswitch near the vegetable oil
tank senses that the coolant has reached the temperature you selected, the
thermoswitch switches on and turns the solenoid valve on. The valve from
the main diesel tank is closed and valve from the vegetable oil tank is
opened. Your Diesel engine does not miss a beat. You notice that it idles
a little more quietly. As you roll down your window to let in some fresh
air, you notice the sweet smell of french fries. Upon nearing your final
destination, you flip the toggle switch to the "off" position.
Electricity stops flowing to the solenoid valve, which instantaneously
switches the fuel source back to the diesel tank. As you pull into a parking
space, your engine purrs along, washing the vegetable oil from the fuel
pump and the injectors. You turn your Diesel off and wonder why nobody
believed you when you told them you were going to run your car on french
fry oil.