Metcalf
Expedition Leader
So I started fiddling with bio-diesel for my dodge.
I am doing some research into some cold weather bio-diesel fuel modifications but I am wondering if a mechanical system might be an easier way to deal with the cold weather bio-diesel jelling problem.
Basic idea. To stop the bio-diesel from jelling, in general it needs to be kept above 40F depending on what oil you use to make it. So the fuel tank, fuel lines, fuel filter, injection pump, and injection lines/injectors need to be kept above 40F no matter what the outside temperature. I think this can be done with a hybrid of a WVO fuel system. A coolant loop can be integrated into the fuel tank easy enough. The fuel lines, both the supply and return could be heated with a tube in hose type system. The fuel filter can be heated with a heater line wrap. It gets a little more complicated to heat the injector pump, injector lines, and injectors. In general, if the coolant in the engine was heated the injector pump may become warm enough, but I don't know if I would count on that. I think circulating heated fuel through the injector pump through the existing supply and return lines may work pretty well. The factory fuel pump on my dodge is mechanical however. Perhaps a secondary electric fuel pump could be used? Does anyone know if you can pump through the factory mechanical pump? Or maybe it would be easier to just branch the fuel line near the fuel filter with some one way valves in order to add in an electric pump. The injectors and lines might be able to be heated by heating the engine block coolant, but again, I don't know if I would count on that. I think wrapping the injector lines in electric heat lines would be a good option. They could be used just prior to starting in order to make the lines hot enough.
Everything above is fairly proven and should work well to keep the fuel over 40-60F even in really cold weather. Once the engine was running the engine coolant would circulate through all these features enough to keep the fuel plenty hot to use in the motor. There might even be a little too much heat!
The big questions are....
-What to use to heat and circulate the coolant?
When AC power is available I would think that it would be very simple to use the block heater to heat the coolant. Adding a small AC electric pump to circulate the coolant through the system would be fairly easy. A thermometer might need to be added to keep everything from getting too hot. This system could be used from a COLD state. The truck could be below 40F and once plugged in the coolant would heat and circulate warming the engine and fuel to above 40F causing a much easier start, and a reliable start on bio-diesel I hope.
What about when AC power isn't available? I have been looking at the Espar diesel fired coolant heaters. It would seem that it would be fairly easy to plumb one into the system that I mentioned. They have a coolant circulation pump that is built into some models too. I haven't been able to find the exact control system with the temperatures I need. The simplest version of the Espar system just has an on/off switch in the cab, when the coolant reaches like 185 degrees it shuts the heater off, but keeps circulating the coolant until it gets down to 175 degrees and then fires the heater back up. The only real downside to this system is that the circulation pump runs off of your 12V battery and there is no way to top it off. From what I was able to find the Espar draws 4 amps on hi and 2 amps on low. While not a TON of power, it is a decent amount that could add up over time to kill the battery. It should work just fine...its just the operational duration that might come to be a factor. The other downside is that this 'independent' system would not be able to start cold since the fuel would be gelled and not use-able in the Espar.
Anyone have any other ideas?
I am doing some research into some cold weather bio-diesel fuel modifications but I am wondering if a mechanical system might be an easier way to deal with the cold weather bio-diesel jelling problem.
Basic idea. To stop the bio-diesel from jelling, in general it needs to be kept above 40F depending on what oil you use to make it. So the fuel tank, fuel lines, fuel filter, injection pump, and injection lines/injectors need to be kept above 40F no matter what the outside temperature. I think this can be done with a hybrid of a WVO fuel system. A coolant loop can be integrated into the fuel tank easy enough. The fuel lines, both the supply and return could be heated with a tube in hose type system. The fuel filter can be heated with a heater line wrap. It gets a little more complicated to heat the injector pump, injector lines, and injectors. In general, if the coolant in the engine was heated the injector pump may become warm enough, but I don't know if I would count on that. I think circulating heated fuel through the injector pump through the existing supply and return lines may work pretty well. The factory fuel pump on my dodge is mechanical however. Perhaps a secondary electric fuel pump could be used? Does anyone know if you can pump through the factory mechanical pump? Or maybe it would be easier to just branch the fuel line near the fuel filter with some one way valves in order to add in an electric pump. The injectors and lines might be able to be heated by heating the engine block coolant, but again, I don't know if I would count on that. I think wrapping the injector lines in electric heat lines would be a good option. They could be used just prior to starting in order to make the lines hot enough.
Everything above is fairly proven and should work well to keep the fuel over 40-60F even in really cold weather. Once the engine was running the engine coolant would circulate through all these features enough to keep the fuel plenty hot to use in the motor. There might even be a little too much heat!
The big questions are....
-What to use to heat and circulate the coolant?
When AC power is available I would think that it would be very simple to use the block heater to heat the coolant. Adding a small AC electric pump to circulate the coolant through the system would be fairly easy. A thermometer might need to be added to keep everything from getting too hot. This system could be used from a COLD state. The truck could be below 40F and once plugged in the coolant would heat and circulate warming the engine and fuel to above 40F causing a much easier start, and a reliable start on bio-diesel I hope.
What about when AC power isn't available? I have been looking at the Espar diesel fired coolant heaters. It would seem that it would be fairly easy to plumb one into the system that I mentioned. They have a coolant circulation pump that is built into some models too. I haven't been able to find the exact control system with the temperatures I need. The simplest version of the Espar system just has an on/off switch in the cab, when the coolant reaches like 185 degrees it shuts the heater off, but keeps circulating the coolant until it gets down to 175 degrees and then fires the heater back up. The only real downside to this system is that the circulation pump runs off of your 12V battery and there is no way to top it off. From what I was able to find the Espar draws 4 amps on hi and 2 amps on low. While not a TON of power, it is a decent amount that could add up over time to kill the battery. It should work just fine...its just the operational duration that might come to be a factor. The other downside is that this 'independent' system would not be able to start cold since the fuel would be gelled and not use-able in the Espar.
Anyone have any other ideas?
