Simpler veg system?

[Rattlenbang]

I was wondering if you can just run the main fuel line through a preheater and just add veggie oil or dino p*ss according to what is handy. That way you can forgo the cost of an extra tank, switch valves, etc. Does anyone know if there's an issue with preheating the dino p*ss? I can't seem to find much authoritative info online about consequences of the inevitable mixing of the two fuels...

[BCDelica]

You can not start the vehicle cold with WVO, or a strong concentration of WVO to diesel. If it just starts, as a vehicle will on a hot day during a non hot start, or a mix a little thick in grease, it is not good for the engine for several reason. Though over the years we had far too many time of forgetting to purge and having to start a cold engine.

In Thailand I came close once to running on 100 WVO (rice bran oil) and our truck barely started after sitting all day in low 30 celsius temperatures.

Not often (enough) considered is a little diesel purge tank, maybe as small as 4 liters, somewhere handy and using the existing tanks as fill with what's on hand tanks.

Oils mixes just fine, in Canada I always ran a loop system where the overflow always went to the diesel tank, yet drove primary on WVO. I just made a point to run the diesel tank almost empty earlier winter, then fill with diesel ensure it was thin enough for winter starting. And that diesel fill would last all winter, mahahaha.

Happy New Year!

[Jordan]

One tank systems are available but are climate specific. I don't think you want to heat petro-diesel too much or you will cook the lubricity out.

[Rattlenbang]

You can not start the vehicle cold with WVO, or a strong concentration of WVO to diesel. If it just starts, as a vehicle will on a hot day during a non hot start, or a mix a little thick in grease, it is not good for the engine for several reason. Though over the years we had far too many time of forgetting to purge and having to start a cold engine.

In Thailand I came close once to running on 100 WVO (rice bran oil) and our truck barely started after sitting all day in low 30 celsius temperatures.

Not often (enough) considered is a little diesel purge tank, maybe as small as 4 liters, somewhere handy and using the existing tanks as fill with what's on hand tanks.

Oils mixes just fine, in Canada I always ran a loop system where the overflow always went to the diesel tank, yet drove primary on WVO. I just made a point to run the diesel tank almost empty earlier winter, then fill with diesel ensure it was thin enough for winter starting. And that diesel fill would last all winter, mahahaha.

Happy New Year!

I understand the need to preheat the oil, but why not an electrical heat exchanger rather than a coolant one? Warm oil from the get-go. The other poster commented about lubricity issues, but I suppose you could simply turn off the juice to the heater if using dino blend...

[BCDelica]

I understand the need to preheat the oil, but why not an electrical heat exchanger rather than a coolant one? Warm oil from the get-go. The other poster commented about lubricity issues, but I suppose you could simply turn off the juice to the heater if using dino blend...

Heating diesel will not change it's, or it's additives, properties as a fuel - unless your system F's up's and boils your pressurized injection lines.

Vegtherm, Elsbett (a single tank system), and others, use electric heat; but that is a lot of current draw and heated coolant is readily available and it's running temp is ideal to heat WVO. I've been told of a Jetta in northern Alberta running a Elsbett system, which I'd like to see what has done to run at these temps.

Thailand hot season, easy; most asian market diesel trucks use very cheap drop in disposable filters for oil and fuel - real cheap ones that fit in the factory filter housings. This includes new models also, and you have to wonder if we will ever adopt this. Unlikely. Staff of mine that earned between 280 to 400 Cdn a month bought new diesel trucks, and I often checked out what the filters were like. if consumables are pricey it's not going to happen. Oil costs are similar, though more choice of budget brands, but an oil filter cost $3-4 Cdn during a oil change. And I bring this up because many people there, me included, were pouring all kinds of oils down the hatch. Everybody wanted our waste cooking oil; for reselling, fuel, and of course to use as cooking oil again.

[BCDelica]

Found what I was looking for from here:

I agree that a single tank system appears to be a simpler and neater solution. However, the single tank Elsbett conversion kits rely on modified injectors and different (longer) glow plugs which stay on longer during startup. Also, the heating of SVO is taking place as close as possible to the injection pump.
In a single tank system the SVO will stay in the injection pump and in the lines feeding the injectors and the injectors themselves. To my mind that still leaves the fuel components having to deal with cold SVO during the initial startup phase. While the physically longer glow plugs may well heat the cold SVO a bit more thoroughly in the pre-combustion chamber and the modified injectors may be better capable of atomising the more viscous colder SVO, all involved fuel components will, at least for a short while, be subjected to higher stresses.
Particularly distributor type injection pumps found in modern diesel engines (Zexel, etc) would be more prone to premature failure under these conditions.
NOT using modified injectors and longer glowplugs would leave your engine vulnerable to even more serious damage: Sticking rings, cylinder wall glazing and piston seizures due to improperly atomised SVO hitting the cylinder walls. This condition can also be caused by conventional diesel fuel in engines with faulty glowplugs and/or injectors and is one of the reasons why most diesel engines make use of pre-combustion/swirl chambers. (Direct injection engines have a deep well in the top of the piston to keep fuel away from cylinder walls.)
Advantages of a two tank system:
Only diesel fuel is used during the most critical startup period.
SVO/WVO is only introduced when all components are hot, thus reducing the likelyhood of premature component failures.
Two completely seperated fuel systems provide fault tolerance. If your WVO fuel system failes due to contamination, low temperatures, clogged filters, etc you can switch back to diesel with the flick of a switch.
All components for a two tank conversion can be sourced by yourself. No need to purchase an (expensive?) kit.
If you like the elegance of a single tank conversion, than you may find the idea of NOT converting your car at all even more appealing. In other words, consider BIODIESEL.
It is not as messy and difficult as it might appear. My experience is that the most messy part is actually collecting and filtering the WVO. Which you have to do in either case!
And finally - before you consider going ahead with the system of your choice, do a simple calculation:
*** The WVO Cost/Benefit Calculator ***
A = Fuel consumption (litres per 1 km)
B = Cost of 1 litre of diesel minus cost of 1 litre of WVO
D = Cost of WVO conversion + cost of injection pump rebuild (ask any diesel repair shop)

Calculate:
A * B = Savings per kilometre
D / (A*B) = Break Even (The number of kilometres your diesel engine will have to run on WVO until it will have payed for the conversion AND a pump rebuild.

Example:
Your cars consumption is 10ltrs/100kms
A = 0.1 litre per 1 kilometre
B = $1.00 (diesel ~$1.20 - WVO ~$0.20 (cost of collecting and filtering))
D = $500.00 + $1500.00 = $2000.00
A * B = $0.10
D / (A * B): 2000 / 0.10 = 20,000kms

Good summary but doesn't mention the effect of incomplete combustion due to failing to atomize/vaporize the waste fuel and the acid like affect on the exhaust system, far more so if the waste oil has a percentage of water in it. Stories are out there of turbos dissolving after several thousand kilometers, the only causes common are improper preheating and contaminated WO.