VeggiBenz Information

PDF of Documentation with PHOTOS

Fill Alarm- a float switch is installed in the tank to warn when it’s nearly full. My filter/transfer system does not have an automatic shutoff system and the flow is relatively low. We found it easy to get distracted and overfill making a mess. The fill alarm is activated with a reed switch when the fuel door is open and chirps when nearly full.

Veg Alarm- a buzzer will indicate the system was shut down with the vegoil left on.

Tank Drain- To drain collected water or crud from the tank the existing tank outlet is used as a tank drain. The suction screen was cut off the top of the fitting. A valve was mounted to the inner fender to allow a quick drain point.

Control Panel-The ashtray was removed and a control panel constructed from aluminum to mount the switches and the diesel fuel gauge. A 5 pin connector was used to allow removal of the panel or the shift console with a minimum of wires having to be disconnected. The wood panel from the ashtray was used to make it attractive.

Hose Routing- It is difficult to rout the hoses around the drive train and exhaust to the trunk. With some research on a parts car, it was discovered there is a path in the side channels that can exit under the backseat and through a plastic plug for access to the shock mount and into the trunk. The hoses enter the car under the drives seat. The hoses pass through tubes attached with U-bolts and sealed to the floor pan. Heat shrink tubing seals the hoses to the tubes.

Hose in Hose (HIH). A counter flow heat exchanger is constructed by routing a 3/8 aluminum tube inside the heater hose going from the engine to the trunk. It was very difficult to make the tight bend under the seat with the aluminum tube. I would recommend using Nylon tubing purchased from a hydraulics supply company. Others use a 5/8” heater hose with the tube inside. It is difficult to pass the fuel tube through the hose barb fitting. This conversion used 3/4” heater hose for the supply and 5/8” for the return.

Coolant Pump- The stock benz auxiliary coolant pump runs whenever the system is turned on. Switchover doesn’t occur until the coolant exiting the tank reaches 150 deg f. I’ve tried it with the boost pump removed and am not sure it makes much difference.

Automatic Switchover- The vegoil system can be activated as soon as the engine is started. A thermoswitch is attached to the coolant line exiting the fuel tank. The switch to vegoil won’t take place until the temp on the coolant line exiting the vegoil tank reaches 150 deg f.

Electric Heat- A glow plug heater is added inline before the filter to add extra heat at startup. A Thermoswitch limits the temp to 180 deg f and resets at 150 deg. At switchover, the heater cycles for the first 5 or 10 minutes. After it’s warmed up a bit I don’t think it comes on very often. Also are installed Fattywagons injector line heaters. They run all the time vegoil is being supplied to the engine.

Vegoil out/disable- a separate toggle switch will allow the stock tank to be filled with diesel (if you can afford it). Flipping the switch shuts off the coolant flow to heat the fuel heating system using a standard benz monovalve and disables all the electric heat. The vegoil switch changes which fuel pump is activated thus which tank supplies the fuel.  I flip it to disable when the vegoil is out or I don’t intend to use it. Heating the tank, particularly when empty causes condensation inside the tank. When making the panel I was working on the back side and accidentally put the led on the wrong side. I had to do something with the hole and added an led that lights when the disable is activated. It’s really not necessary.

VegOil- On a trip of 15 min or more, activate the vegoil as soon as the engine is started. When it gets to operating temp, it will turn off the electric diesel pump and start the vegoil elect fuel pump. The light will glow above the switch. About 5 min before reaching destination, switch back to “diesel” to purge the vegoil out of the engine. For stops of 10 or 15 minutes it is not necessary to purge the system. If it is shut down with the vegoil left on an alarm will sound. Restart the engine and allow to idle for 5 min or so. I suggest you don’t leave the car running and assume you will remember to come back and turn it off. I have found it does quit by itself when it runs out of diesel! Don’t run it out of fuel on either tank. The system has to be purged and it is not easy. I have found it will run 60 mi comfortably after the low fuel light comes on for the veg tank. An 11.5 gallon tank for diesel is in the trunk.

Diesel Only- if the vegoil tank is out of oil. Switch the right toggle to “vegoil out/disable”. This kills the system and the both tanks can be filled with diesel. The left switch selects which tank is used. Up is the main tank (normally vegoil) and down is the trunk tank.

Filters- there should be spare filters in the trunk. Diesels are very sensitive to plugged filters. If there is a reduction in power, particularly noticeable when accelerating or going uphill, the filters are likely plugging. When changing the filters the air must be purged out of the system before stating the engine. A diesel can’t tolerate any air in the system. The systems are independent and if there is a problem with either system, the other is still useable.