300tdi Veggie Oil Conversion - Fuel Pump Question

[mike_ie]

Hey all. This is more of a technical question, hence me posting here, rather than in the alternative fuels section. I've recently cone across a reliable source of very cheap, filtered waste vegetable oil ($0.20 AU per litre), and have been looking into getting my 110 to run on it.

My defender has a dual tank setup - at the moment one overflows into the other when filling, but I plan to make one of them a dedicated WVO tank - and I understand the principles - heat the fuel as much as possible (FPHE and heated fuel filter) along the way to improve viscosity, and filter it, I just need to work out one or two of the technical aspects regarding getting WVO to the engine.

My understanding is that diesel is pulled into the engine through the use of a lift pump - in other words, no fuel pump on the diesel tank, but I'm guessing that I will need a dedicated fuel pump to push the thicker WVO from tank to engine. How do I control this? Do I need to worry about a pump that, say, pushes through 15 litres/minute into an engine that doesn't require this amount of fuel? Is there a return to the tank for unused fuel, and if so, can I just use any inline pump??

Any help would be appreciated.

[Michael2]

I looked into this awhile back and these were my concerns :

With regard to fuel lubricosity : I don't think you'd get the WVO above 80.C and for it to match the lubricosity of diesel it should be up to 160.C.

[Blknight.aus]

I run the exhaust pipe along the main fuel tank that pumps the Wvo, from there a facet pump (via filters of course) shifts it into a dedicated heater/surge tank inside the engine bay and it spills back to the WVO tank

the surge tank has a pickup point for another facet pump to draw the now heated WVO through another filter and deliver it to a hydraulic 6 port valve.

when switched to WVO both facet pumps run and the 6 port valve connects the tank side lines to the engine lines

when switched to diesel the facet pumps are off, the 6 port valve connects the diesel tank lines to the engine lines and an external tank pump lifts the diesel from the diesel tank to the pump via 2 filters.

All the filters have a water seperating capability with the exception of the final fuel filter.

The main processing tank in the back has a heated floor and a hook up point for a vacuum extractor to draw the water out of the WVO.

I generally blend 140l of wvo with 20l of dieso in the processing tank and If im having trouble running on that add more dieso to the usage tank on the passanger side of the vehicle.

When its warm enough I run WVO with no problems at 100%

[mike_ie]

I run the exhaust pipe along the main fuel tank that pumps the Wvo, from there a facet pump (via filters of course) shifts it into a dedicated heater/surge tank inside the engine bay and it spills back to the WVO tank

Hmmm, you have given me room for thought here. I was actually looking into getting a stainless tank with built in heat exchanger made to replace my existing auxiliary tank (found a guy here that does very cheap stainless work), but having a small heated tank constantly flush heated fuel through the main tank should be a much cheaper option.


the surge tank has a pickup point for another facet pump to draw the now heated WVO through another filter and deliver it to a hydraulic 6 port valve.Why does it need to be a six port valve???


when switched to diesel the facet pumps are off, the 6 port valve connects the diesel tank lines to the engine lines and an external tank pump lifts the diesel from the diesel tank to the pump via 2 filters.Does the diesel tank now need an external pump?? Will the existing factory setup not be sufficient???

Any chance of a rough estimation of how much your setup cost??? Or photos and a more detailed explanation?? Any input at all would be greatly appreciated.

[Blknight.aus]

if you want to switch entirely from WVO to dieso you need either 2x 3 port or 1x 6 port.

logically

tank 1 supply
----------- engine fuel system.
tank 2 supply

tank 1 return
------------engine fuel return
tank 2 return

no the diesel doesnt need the external pump but doing without it makes the plumbing easier (mine was leaking nayway so I just looped it out of the system)

my setup was cobbled together for maybe $300 the most expensive part being the valve everything else I had on hand.


eyeball this thread

http://www.aulro.com/afvb/projects-tutorials/61593-fozzy-ccccc-prep.html

its got the rough out of the existing system.

I havent got a full set of pics yet but if you're brissy based (or anywhere on the CCCCC route) you're welcome to come have a look see in person

[camel_landy]

You could always just take the oil and convert to Bio-Diesel??

Once converted, you should be able to run it through without any conversion at all.

M

[Blknight.aus]

correct and that was the initial plan for fozzy but I didnt want to run the risks involved in carrying the chemicals to make it on the road.

the bueaty of the WVO setup is if you get it just right you can pull up at a fishnchip shop, fill the WVO tank and drive off...

Im having some problems with mobile prefiltering and the fact that most of the places around here have switched from vege oil proper to copha which carries more water and has to be even more meltied before it can be pumped. This is especially problematic now that its winter.

I'm working on it.