Vegoil conversion are surprisingly simple. All you are trying to do is provide hot vegoil to the injectors so it will spray into the combustion chamber similarly to diesel fuel. Heating the vegoil thins it to a lower viscosity closer to that of diesel fuel so it can be easily atomized and combusted inside the engine. No modification of the engine itself is required so the mechinical skill and funds needed to convert a diesel to vegoil is fairly minimal and within reach of many common folks....and well within the ability of any mechanic. The kits which are available for converting diesels to vegoil are composed mainly of components which warm the vegoil from ambient temperature to around 150*F -200*F before it is pumped to thje Injector Pump (IP). As the vegoil is sent under high pressure from the IP through the injectors it is further warmed by pressure and the heat of combustion which has been transferred to the injectors themselves. So as the vegoil passes through the injectors and into the prechamber of Indirect Injection (IDI) engines or is swirled onto the deeply cupped piston tops of Direct Injection (DI) engines. Vegoil cannot be used as a fuel in gasoline engines...only diesels.

  Some diesel engines are designed to run on a fuel known as Bunker Fuel which is a very thick..almost tar like petroleum product left over when lighter fractions like gasoline and diesel fuel are distilled from crude oil. These are mainly the huge marine diesel engines which power ocean going ships and the fuel systems in these vessels are very similar in design to the components used in most vegoil conversions. These components consist of a tank heater or heated fuel pickup, heated fuel lines, heated filters, and preinjection fuel temperature boosters. In bunker fuel systems the injectors themselves are sometines heated to help boost the temperature of the bunker fuel. But in the smaller diesel engines used in cars and trucks the injectors are heated to the temperature of the heads they are screwed into. In fact they are usually hotter than the surrounding metal of the head since they are exposed on thier lower ends to the heat of combusting fuel. This is a very handy coincidence for those considering converting to vegoil fuel since it allows a minimum of heating components to be required for conversions...simplifying and lower the cost of the process.

For DI diesel engine conversions I recommend a pre-IP vegoil temperature of 140*F to 160*F. The majority of this heat can be supplied by the coolant using simple fuel/coolant heat exchangers. Normally the maximum temperature that can be achieved using only coolant heat is around 120-140*F. After as much heat has been added with coolant/fuel heat exchangers as possible 12vdc electric resistance heaters are used to boost the vegoil fuel temp further if  needed. These also speed the heating of the fuel allowing a shorter time to when "switchover" to vegoil fuel from diesel is possible. In very warm climates where the ambient temperature never drops below 65*F it is possible to convert some vehicles simply by installing an electric fuel heaters and adding prefiltered vegoil to your existing fuel tank. For those living in less tropical regions of the world the conversion is a bit more complicated..but still relatively simple. Generally speaking the colder the climate you plan to use the engine in the more fuel heating components that must be used to allow dependable use of vegoil and full power availability. If the vegoil is used fryer oil (WVO) which can contain large amounts of fats and tallow the fuel may solidify at room tempature and be rock solid at below zero temps. To allow use of wvo in all but tropical climates a tank heater must be used to liquify the fuel so it can be drawn through the fuel lines. And because any liquid wvo in the fuel lines will also be solidified at ambient temperatures the fuelines must be heated so this wvo is also liquified and  so allow fuel from the tank to pass. Luckily internal combustion engines produce a large amount of waste heat which is usually gotten rid of via the radiator. A small amount of this heat caneasily be diverted to provide the majority of the energy used to warm the vegoil from whatever the ambient temperature is to up to 140*F.

begin here

Since most diesel engines will not start on cold (but liquid) vegoil unless they are warm either a means to heat the engine or a "start/purge" fuel must be provided. In areas where the ambient temperature never drops below 45*F it may be possible to simply add a block heater to warm the engine with house current before starting. This of course ties you to the chore of plugging in the block heater to house current for at least a half hour whenever the engine has been shut off long enough to cool to ambient temp. It may be much better to consider providing a second fuel circuit to provide for a "start/purge" fuel. With most vehicles this is the preferred method of conversion. It allows the engine to be started normally (on diesel fuel) and then within a few minutes switched over to vegoil.

Another consideration is that some vegoil (especially wvo derived fuels which may contain fats) may thicken to the point they will not readily flow through the fuel lines unless they are warmed a bit. Coolant heated fuel lines and tank heaters (which warm the fuel in the vegoil tank) are the simplest answer to this and the preferred conversion method since most vehicles do not have enough electrical generation capacity to power much more than the 12vdc fuel "boost" heaters previously mentioned. The vegoil fuel tank heater may be installed fairly easily in the existing fuel tank but then a smaller tank must be provided for the start/purge (diesel) fuel unless the vehicle has dual fuel tanks already. In vehicles that do not have dual fuel tanks it is usually simplest to have a small round fuel tank fabricated which fits in the place of the spare tire or use a slightly modified 5-20 gallon plastic "marine" fuel tank secured in the trunk which is used for vegoil fuel. In very cold climates it is possible to also install a house current powered vegoil tank prewarmer in any tank used for vegoil fuel.

While it is possible to use manual valves to provide a way to switch form one fuel to the other it is much simpler to use solenoid valves. I recommend using a 6 way solenoid valve since they will allow a single unit to switch both the fuel supply and return circuits simultaneously. Two 3-way solenoid valves may also serve the same purpose. Both 3 and 6 way solenoid valves are available as new units or can be salvaged at junkyards for less than 1/2 the cost. The solenoid valve is connected to a switch (on-off-on) on the vehicle dash which is used to switch from one fuel to the other and is plumbed like this.

These are a examples of some basic conversion configurations.

All fittings and connections must be secure so no air leaks are possible.