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Old January 12th, 2010, 12:13   #5
Veteran Member
Join Date: Feb 2008
Location: Maryland
TDI(s): 2001 Jetta
Default Congrats Your Ready for the Conversion

Congrats your ready for the Conversion

At this point, you are chomping at the bit to start burning WVO and doing so successfully. There are many options out there to decide from, so many that will make your head swim. I will discuss the three approved kits. They are kits that come with all the parts and assemblies for you to install it on your car. Note: I said YOU install on your car. I will stick to Greasecar, Frybrid and Elsbett. I will discuss the advantages/ disadvantages of all three. My experience has only been with the Greasecar kit; however, I know enough to comment on all three and understand the most important aspects of a kit.

Two tank conversion kits include Greasecar and Frybrid, let’s look at the mandatory requirements of a two tank conversion.

2 Three Port Switchover Valves-
Two three port valves ensure very little to no cross contamination occurring between fuels (WVO and diesel). This is the art of the two tank kit. Having 2 three port valves keeps the WVO out of the main diesel tank. Now a little bit of cross contamination will occur, but it is negligible at best if you follow purging requirements. The art of a two tank is to start on 100% diesel and to stop on 100% diesel. Keep it that way, purge correctly and for enough time. You should also drive on diesel long enough to purge not only the WVO supply line, but the injection pump, injector lines, injectors and the combustion chamber. Let that TDI rip, they are fun to drive, USE IT. The six port Pollack valve that was used on some kits is not on the approved list for a two tank kit. The six port Pollack, although simplifies fuel line hose routing, has been known to fail and has no means of preventing cross contamination. STAY AWAY from it… remembering that the art of a two tank is to start on 100% diesel and to stop on 100% diesel. The six port Pollock was commonly found on Golden Fuel systems and Greasel conversions. Plantdrive also offers a six port Pollock available on their website for sale. A six port Pollock valve means almost certain death to any diesel engine if it is used… (Two- Three Port Valves Mounted)

Heated Fuel Filter-
The filter must be heated because this is the first source of supply WVO when switchover occurs. The idea is to keep everything heated and to not send cold WVO (molasses) to your pump when you switch to WVO. This should be the last stop for your WVO before it hits the injection pump. A lot of people like to put a vegtherm in between the heated filter and the injection pump because this part of the hose is not heated. I like the idea based on that fact; however, I do not like the idea that electric heat is unregulated. Since electric heat is unregulated and the vegtherm itself is a metal piece, polymerization of the oil could possibly build up in this spot over time (through continued heating of the WVO and consequential cooling through use of purging with diesel fuel). This theory has not been proven; however, if this was to occur, this would allow unfiltered polymerized pieces of WVO to be sent to your injection pump. I know if a filter is the last stop before hitting the injection pump, I don’t have to worry about this. Lucky for us, there is a more effective way of heating the oil that avoids this completely. Injection line heaters… this will be explained later.

HIH vs. HOH-
Both of these kits offer HIH (hose in hose). Let me explain what that means. HIH (hose in hose) means the supply WVO line from the tank in your trunk is submerged in a coolant line that goes back to the tank for the heat exchanger coil. As the car warms up, the entire supply line (usually PEX) sits in heated coolant, thus providing a great heat exchanger. HOH (hose on hose) means the coolant that goes to the tank for the heat exchanger coil in the tank sits on top of, or as close as possible to the WVO supply line, thus not a very good heat exchanger. The advantages of this are you will never run into cross contamination of coolant into your fuel. However, in my research, it is extremely rare to hear of PEX line breaking down to where coolant contamination of the fuel would occur. If this was to happen, chances are the PEX line was kinked during the install and therefore weakened. HIH is the best way to go because this is one of the best heat exchangers available. Using HIH and a FPHE, my oil is ready to be injected when the engine reaches operating temperature even in the winter. You can’t ask for anything better than this.

Fuel Level Gauge-
This is pretty obvious. You always want to know how much WVO you have in the secondary tank. (WVO Gauges) (Another View)

FPHE (flat plate heat exchanger) is another effective means of final heating the WVO before injection. Unfortunately for Greasecar, it is an optional item, but should be standardized and is highly recommended on the TDI. Frybrid makes this a standard part of their kit. Not only will a FPHE heat the oil extremely well, it will regulate it at that temperature. With a FPHE, unless your in the extreme dead of winter (20 deg and below), typically once you reach operating temperature your very close to being able to inject the oil and start burning it. and Heated Filter)

Heated Tank-
Both kits come with a 13-15 gallon secondary tank that replaces your spare wheel in your tank (can also opt for a square tank if you don’t want to remove your spare). The 13-15 gallon tank comes equipped with a coolant exchanger (typically a copper coil). Some people say this can get the oil too hot and can cause polymerization of the coil and the oil. Polymerization is caused by oil being exposed to extreme heat and air/ agitation. I can not comment on this so far as we checked our coil on our Powerstroke after 22k WVO miles and it was spotless. People have reported problems with excessive polymerization at or around 100k of WVO use. Signs of this would be changing the WVO filter more frequently then what is expected. The basic idea behind a heated tank is to heat the oil enough to flow, not to heat to injection temperature. People have looked into a third valve that cuts coolant supply off to the WVO tank to prevent excessive heating and therefore consequential polymerization. Although a great idea, I have not done this myself. What I do try to do is to keep my tank over half full at all times. This limits the amount of air available in the tank and therefore room for the WVO to move. Also keeping the tank half way filled up will prevent the coil from being exposed to air and thus, avoiding this problem entirely.

These are the basics of the kit that are mandatory. Frybrid and Greasecar also supply all the fittings and valves to make this all work. Both of these kits have what I like to call “flashy items.” Frybrid offers an LED panel that shows what fuel you’re on. Greasecar supplies an optional handheld computer device that purges for you at the push of a button and also tells your coolant temperature. In my opinion, all this does is make the kit complicated. I have a simple switch that I flip and I always know that if the switch is flipped a certain way; I am on a certain fuel. Computers are much more prone to fail. These kits have a fail safe to default to diesel fuel if anything goes wrong; however, I abide by the KISS method (keep it simple stupid). Also, you are much less conspicuous with just a switch on your dash. If you get pulled over or have friends in the car, be prepared to explain that you burn WVO. Enjoy explaining that to the cops! (WVO/Diesel Switch)

With only a kit installed on your car, you’re accepting a bare minimum means of injecting WVO in your TDI with little or no modifications made to the car to do so properly. (Greasecar Kit Installed Properly) (Close Up) (Entire Engine Bay)
2001 Jetta TDI- 190K
17/22, T4 764's, KermaTUNE, Euroject SMIC, Southbend Stg2 Endurance Clutch, LSD, .681 5th

WVO no More 187k
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