Results 1 to 1 of 1

Thread: WVO Dual Tank Findings

  1. #1
    Join Date
    Oct 2005
    Sunshine Coast, QLD

    WVO Dual Tank Findings

    Hi all, just throwing together some good hits I'm finding in the research phase of my conversion. I thought I might get over my self and start contributing again. Hope this of benefit.

    Thanks to Robert, Captain Echidna, Fitian, 98troopy ,Tony From West Oz, Steve-Kal, froggo for being inadvertently contributing to this post.

    PRO's of Dual conversions
    • No chemicals kept around house (kids friendly)
    • Reduced costs
    • Great for long trips
    • No excise, chemicals, heating, mixing, chemistry calculations.
    • No bi products - Glycerine
    • no ongoing processing - just filtering
    • One off engine change over

    CON's of Dual conversions
    • Hassle of having to start-up and purge before you shut down with diesel/biodiesel (is it really a hassle - turbo timer?)
    • There are studies showing that SVO is not so good long term for an engine used for short trips, stop/start driving etc in terms of cylinder coking etc (citations?)
    • Hopeless for short trips - less than 20 klms.
    • Hard starting if you forget to flush out.
    • Needs two tanks, which often takes up space in car
    • Manual process of conversion (unless you know Fitian)
    • May not suit newer Comon Rail Injection type diesels (citation correction needed)
    • Ongoing of filtering oil can hassle

    Quote Originally Posted by 98troopy View Post

    So to summarise, from my point of view:

    Option 1, do nothing:
    Fuel costs $1.50/litre (average). (as at Jan 08)
    I hate the smell, both raw and burnt.

    Option 2, use commercial B100:
    Fuel costs $1.20/litre (guess).
    I have to drive 50 km to Rutherford or 150 km to Marrickville to fill up.
    I have heard that B100 can damage paintwork if spilt.

    Option 3, Make B100:
    Fuel costs $0.10 - $0.50/litre (estimates).
    I have to collect and filter oil (time and effort).
    I have to buy Methanol ($1/litre) and caustic soda (very cheap?)
    I have to convert filtered oil to biodiesel (more time and effort).
    I have to handle methanol and caustic soda.
    I have to store and dispose of methyl glycerol.
    I have heard that B100 can damage paintwork if spilt.
    I get sig' less than 1 litre of fuel from each litre of filtered oil.
    Filters should last as long or longer than for diesel if I have filtered properly.
    I feelbad about not paying excise.

    Option 4, 2 tank SVO system:
    Main fuel costs $0.00/litre.
    Start-up fuel costs $1.50/litre (unless I can get some bio from a home maker)
    I have to collect and filter oil (time and effort).
    Vegetable oil is good for paintwork and protective against rust.
    I get 1 litre of fuel for each litre of filtered oil.
    I have to start up on diesel (or B100) and purge before stopping (possibly idling in driveway if I forget).
    I have to pay one off for conversion.
    Filters should last as long or longer than for diesel if I have filtered properly.

    Option 5, single tank SVO system:
    Fuel costs $0.00/litre.
    No start-up fuel required.
    I have to collect and filter oil (time and effort).
    Vegetable oil is good for paintwork and protective against rust.
    I get 1 litre of fuel for each litre of filtered oil.
    I neither have to start up on diesel nor purge before stopping.
    I have to pay more than option 4 for one off conversion.
    Filters should last as long or longer than for diesel if I have filtered properly.

    So for me it was just a decision between 4 and 5.
    Since I do mainly longish trips and hope to find an amateur bio producer locally (informal co-operative) and would be having 2 tanks anyway it was no contest. Option 4 for me. Others may find other options more suitable.

    Oil Filtering

    • Time is on your side. Allow your oil to settle and you can recover 80-90 % of your oil with very little particles. Water will also settle out and will fall to the bottom.
    • Pouring all of your oil together will allow all of you oil to settle together and you can potentially have 150 litre of oil on top that is easily recoverable. Rather than the manual handling nightmare of pouring 10 - 15 litre from the top of 20 litres drums.
    • In summer your dregs may be even more reuseable, as some higher melting point fats\oils may melt at the higher ambient temp.
    • Cold filtering will allow any solid oil particles to either fall to the bottom (before filtering) and not present while filtering. But will be slow.
    • Heated filtering is quicker but can melt solid oils/fats that may resolidify in your fuel tank and cause blockages.
    • 5 micron filter is a good starting point to filter good clean oil. They may clog over time and may need to be cleaned with heated oil to flush out/melt the oils that collect in the filter.
    • There are upflow systems that allow for recovering of oil from the top of the drum, meaning the crud and water stays at the bottom as describere here -

    Quote Originally Posted by Tony From West Oz View Post

    Your best insurance would be to use well settled, cold filtered vegetable oil. If the oil is stored in an uninsulated building, it will quickly drop to ambient temperatures and any high melting point oils will drop out over a couple of days. By using the oil from the top of the container, you should have the best oil to use in your climatic conditions.

    As the weather warms up, the oils which have solidified will melt again, providing liquid fuel for the warmer months.

    Drying your oil
    • Wet oil will damage you injector pump, valves, cylinder bore and fire deck.
    • Visual inspection of oil will assist to deterimine if oil is dry but isn't the only test
    • Clear oil generally is dry, cloudy oil generally is wet or starting to solidify. Further testing will help assist to determine possible water content of oil
    • A quote from Tony From WA will assist here.

    Quote Originally Posted by Tony From West Oz View Post
    While vacuum distillation is good technique to remove water from oil, the fact that it was boiling indicates to me that there was way too much water there when you started.
    The absence of boiling does not indicate that the water is all gone.
    You should try a hot pan test to verify that the oil is dry.

    Hot Pan Test :
    Smear some oil on a frypan.
    Heat the frypan until the oil smokes
    Add 1 teaspoon of oil.
    If the oil spatters it is Very WET!
    If it sizzles a little, it is Wet
    If it shows some small bubbles it is almost dry and
    If it does not show bubbles but has the heat waves visible, it is DRY!
    Almost dry oil can be used to make biodiesel successfully.
    WET oil is likely to promote the production of soaps.
    The creamy colour of the batch has me thinking that the contents are mainly soap.

    The process can react in 15 minutes or less at 50C if the batch is homogeneous.

    A couple of factors which affect the reaction time are:
    • reaction temperature (40 - 60C is recommended) 10C increase will halve reaction time.
    • effectiveness of the mixing method - a small pump on a large reactor will need more reaction time (pumping time) to effectively mix the batch, than a large pump on that reactor.

    I hope this helps,

    CAV Filters
    (using B100 but still relevent)

    Quote Originally Posted by Steve-Kal View Post
    Good and bad filter elements when using B100

    My experience of filter elements for the Lucas/CAV system when running B100 (mixed veg oil feedstock) in Kalgoorlie during summer (can't run B100 during winter - gels up).

    Ryco filters (R2132P) block rapidly - caused fuel starving stoppages (once after only 800km). I went through 6 filters and all had similar performance.

    Valvoline filters were marginally better - car stopped after ~ 1500km

    Cooper filters (522) best performance yet, lasting up to 5000km

    I cut the filters open after use to investigate. Findings:

    Ryco showed no obvious signs of dirt blockages - filter looked clean. It did however cause the car to stop - even with the assist of the inline electric fuel pump (filter on the discharge of the pump) and a fuel heater it still stopped the car. I did note that the Ryco had significantly less filter paper area compared with the other brands.

    Valvoline showed no obvious signs of dirt blockages - filter looked clean. Same story as the Ryco. It did have more filter paper area than the Ryco though.

    Coopers - same story, no obvious signs of dirt contamination. It had the largest filter paper area (more pleats to the filter element).

    My filter blockages are not due to particle contamination. I suspect that the filters are being clogged with some gel or wax like substance in my biodiesel. In an attempt to extend the filter change intervals I washed the BD 5 times (until wash water was clear) and double filtered it (using the original Jackaroo fuel filter) prior to filling my tank with it. I run the inline fuel pump and used the Raycor fuel heater and a heater on the Lucas filter element (thinking that the heat may melt any gel build up). Still the filters failed as above. I have since moved house and have not set up the BD plant so am running on Gull B20 Diesel. The filter blocking problems have dissappeared.

    1. I use Cooper filter elements (over Ryco and Valvoline) for B100.
    2. I change my filter elements every 2000km when running on B100.

    Vehicle Details

    I run a 1994 Holden Jackaroo with the Isuzu 4JG2 3.2L Turbo Intercooled engine (Bosch Distributor Type Injection Pump) - all standard. I run the standard water trap plus a Raycor (Parker) 6401N fuel heater/water separator and swapped the standard filter with a Lucas/CAV type. I have an electric heater on the Lucas filter element (for winter use only) and an electric inline fuel pump just before the Lucas filter (that has failed after only 1yr of BD100 use).
    Switching Valves

    Pollak Valves -
    • Made out of plastic
    • 6 port
    • inlet size is 3/8'' ( 9.5mm )
    • Designed for ambient temps between -40F and +180F
    • Evidence of failures at high temps
    • Possibly leak between tanks (vege oil into Diesel tank)
    • Valves are rated for fuel delivery system pressures to 65 psi
    • Gasoline and Diesel Fuel systems only (per Catalogue)
    • Failure causes no fuel to flow

    Sirai L340
    • Specifically designed for Heated WVO
    • 3/4" ports ( 19mm )
    • viton seal
    • 3 port valves (2 needed)
    • Temp rated to 130 Degrees
    • Body Anodized aluminium


    Heating of the oil is necessary to increase viscosity lowered to allow for proper atomisation of the fuel, otherwise incomplete combustion and carbon build up will ultimately damage the engine. It will also reduce the load on the Fuel Pump.

    The engine is started on diesel, switched over to vegetable oil as soon as it is warmed up and switched back to diesel shortly before being switched off to ensure that no vegetable oil remains in the engine or fuel lines when it is started from cold again. (

    FPHE (Flat Plate heat Exchangers)
    FPHE are now standard componenets when considering a WVO or Dual setup conversion. They transfer the heat from the engines cooling system into the vege oil. The do this very efficiently and are compact and are very easy to install.

    A vertical orientation is generally recommended with both intake port placed at the bottom allowing any air bubbles to flow up and out of the system.

    Adding foam or insulation over the FPHE will increase its efficiency.

    Quote Originally Posted by Fitian View Post

    I recommend installing a heat exchanger before the wvo filter to melt any fat build up. It makes the wvo flow easily throught the filter without putting any load on the fuel pump.

    I also recommend installing another "smaller" heat exchanger before the IP that shares both fuels. This to gradually warm up the IP and prepare it to receive heated wvo when you change over to avoid thermal shock. Also when you change over from wvo back to cold diesel/bio - the 2nd heat exchanger warms up the cold start up fuel before it enters the well heated IP again to avoid causing thermal shock.

    You can use a single coil heat exchanger from "helton" before the IP to avoid long purge.

    I understand everybody wants the shortest purge possible. One heat exchanger before the wvo filter will get the oil flowing but as I explained there is more to it.
    Hose-in-Hose heater

    This concept allows for an oil hose to pass through a heated water hose.

    Last edited by joe; 6th October 2010 at 08:45 PM. Reason: update OCT 2010


Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts