Conversion Accessories

Written by TsTDI

EGT Gauge-

I wanted to take the time to explain a further importance of having an EGT gauge on any diesel. Other than finding a critical component of the puzzle that is burning WVO in a TDI, an EGT gauge is a wonderful tool to have on a car because it lets you know what is going on with combustion at all times. I told you before in this guide, when you start off with a car that is in good shape, maintained well and up on all scheduled regular engine maintenance, comparisons can be made when burning WVO. Anything out the ordinary will raise eye brows and therefore, will alert you to a problem long before catastrophe ever occurs.

I have heard of a lot of horror stories regarding WVO. I have heard of piston wall scarring, piston ring coking, burning holes in the tops of pistons and injector streaming. Because all of these horrible scenarios have to do with combustion, an EGT gauge will reflect this problem with registering hotter EGT’s. Think about it, if you’re injecting fuel and its not combusting, your engine is producing a lot of heat and pressure and no energy for combustion.

I love having this gauge on my car and observe it on a frequent basis. I always know what is going on with my car and therefore, will always be able to catch a problem before an even bigger one develops. These are preventive ideas that save a lot of heartache. Anal yes, necessary maybe, but what are we trying to achieve and how many people have failed miserably at it?

Lift Pump-

A lift pump is a required piece on a PD engine conversion because the fuel system has no means of drawing fuel from the tank. Unlike the PD engine, the VE rotary injection pump has the capability of drawing/priming itself fuel from the main diesel tank. However, because the injection pump is drawing a thicker fuel, this places undue stress of the pump that is not needed.

Other than providing a performance boost, a lift pump ensures the injection pump always has an adequate amount of fuel supply. With a lift pump installed, no longer does the injection pump have to "work" to get its supply. A lift pump or pusher pump does the work for the injection pump. This prevents the injection pump of ever being starved for fuel and therefore means more power always on tap.

In talking with Greasecar and other people who burn WVO, all of them recommend a lift pump for the benefit stated above. When you switchover to oil, chances are the injection pump will suck a small amount of air before it primes itself fully with fuel. A lift pump helps this process along. The only way to put a lift pump on a Greasecar setup is on the supply line leading straight to the pump. You can’t place the lift pump on the WVO fuel lines because you have to purge that line with diesel and lift pumps will only flow one way. Placing the lift pump on the supply line also has the benefit of always having a lift pump no matter what fuel you are on. Its cheap insurance and an idea that is worth noting, I highly recommend it. I noticed a big bump in on tap power while on WVO with this modification.

http://forums.tdiclub.com/showthread...lbro+Lift+Pump

Here is the lift pump that I use described in a great thread by another forum member. I also opted for the "on-demand" lift pump in which the pump only cycles and pumps to keep the preset pressure within range (anywhere from 4-7 PSI). In other words, the pump doesn’t continually run at 7 PSI of pressure. This could actually work against the injection pump and force feed it fuel that it doesn’t need. An on-demand version of a lift pump means the injection pump gets the supplied fuel when it needs it.

Injection Line Heaters-

The benefits of injection line heaters are numerous. The biggest advantage to using injection line heaters is it’s another source of supplemental heat. On my setup, the oil travels to a FPHE, to a heated filter, to my injection pump and then on its way to combustion. The oil sitting in the injection lines is heated through use of line heaters. The art of injection line heaters is that the WVO has already been pressurized by the pump. Therefore, post IP heating is safer and puts less heat stress on the pump.

Injection pumps are a simple design but do not like excessive amounts of heat. Currently, my WVO temperature from read the fuel temp sender prior to my resistor mod was 180-185 deg in the summertime. I do not know if that is too hot or not. In my time of burning WVO, it has shown to not be excessive and my pump has handled it fine, the car produces a lot of power and still has the same pep that it does on diesel fuel.

This is why electric heating I think is saved best for post IP. Electric heating has no regulation; it just heats until you turn it off. My FPHE not only heats the oil to near coolant temperatures, it regulates it at that temperature. Using post IP heating, you can heat the oil to no end and it no longer matters. There is nothing beyond the pump that could cause potential problems from too much heating; however, there are things beyond the pump that can cause potential problems from too much viscosity (aka not enough heating). The only thing beyond the pump is injection lines that feed four injectors. Take advantage of this by using safe supplemental electric heating.

My observations using injection line heaters have resulted in hotter fuel return line temperatures. Return line is basically the fuel that was not used in the event of injection. I can’t really give you any specific numbers because the sender isn’t all that accurate; however, it has read higher temperatures. In conclusion, injection line heaters are a safe method of heating the oil that much closer to the needed temperature of achieving similar viscosity of diesel fuel.

Water Injection-

This has been an interesting topic that has come up on the occasion in discussing WVO and preventive maintenance. Water injection has been known for a long time to be a performance enhancer by mixing water and methanol (another fuel source) together. Straight water injection is known to "steam clean" the combustion chamber because you can’t compress a liquid. Basically the tiny water particles absorb the heat from combustion and "steam clean" anything the water particles come into contact with. This could result in cleaning any residual coking that could occur on injector nozzles. There has been discussion that water injection could possibly steam cleaning piston rings which is the primary culprit of piston wall scarring (piston rings separate the combustion event from the engine oil that lubricates the internal rotating engine parts). I have a water injection system on my car but I really don’t know if it has benefited me or not. The steam clean theory itself makes logical sense to me however. Let us delve into this further.