Alternative fuels > Straight Vegetable Oil

Changfa Direct Injection engine

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As Dennis said, the key is to get the veggie oil good and hot before it hits the injector.  If you can get it up to 100C that would be great.  The idea is that the hotter the oil, the easier it flows and is less likely to cause misfiring and injector problems.  There is a fellow in Kansas running all of his diesel engines (Listers, road trucks and farm equipment) on a mix of 1 gallon of RUG (Regular unleaded gas) to 10 gallons of fresh pressed Sunflower oil.  He reports better gas mileage and more power.  I have done limited experiments with WVO and gas, but it was pretty cold at the time.  I found that the engine ran well (a 3 cylinder Perkins in a small tractor) on the mix but it did need to have th glow plugs on for a much longer period.  I think this was just the cold (it was 0C or colder) and as soon as spring arrives (10cm of snow this morning in Eastern Ontario) I'll try it again.

greetings my name is bear( have a changfa 13hp. i would like another.can you guys tell me where i can get one.also have you tryed rapping fule line around exosst pipe to preheat wvo.or sump oil'thanks bear

  Fuel that is too hot supplied to the injection pump will make it fail. The diesel Hummers in the middle east conflict have more problems with ruined injection pumps than bullet holes.
   Heat the line between the injection pump and the injector if you must.
   Then again if the engine is operated with coolant temps of at least 195F and 210F is better for heavy oils. The fuel passing through the injector should already by hot and thinned out?

The injection pump on the GM 6.2/6.5 diesels sits in the valley, smack in the middle of the engine.  It gets hot anyway.  I don't think heating the fuel/oil to coolant temperature before hitting the IP will cause it ANY harm.  I have about 25k miles of WVO (205,000 miles total) on a '95 Suburban without (known) issues.  The rotary IP is not very robust to begin with, and with all the sand, dirt, and dust in the area, I believe fuel contamination, and poor fuel lubricity is more likely to be causing failures than heat.  NOT heating the fuel prior to the IP is more likely on these to cause issues.  I've seen reports on GM diesel forums of unheated fuel being too thick contributing to pump shaft failure.  On my setup, both fuels (diesel and WVO) go through a flat plate heat exchanger prior to the IP.  That way, when I switch fuels, there is no thermal shock.



I have experience running WVO in a Changfa S195 engine. The fuel was unheated and was blended with dino-diesel.
I recently posted this information on the MicroCogen forum. Below an excerpt which may apply to this discussion....

In point form:

1] If you are not planning to preheat the fuel, then blending WILL be necessary to bring the liquid as close to that of diesel as possible.

2] There have been many people who use regular unleaded gasoline (RUG) or dino-diesel with reportedly good results. Bare in mind that the RUG does a good job of thinning the WVO but adds little to (or even takes away from) the combustion process because of it's reluctance to auto ignite under compression. Hence reducing the overall cetane value of the mix.

3] If RUG is used as the diluent, consider using a cetane booster to restore some cetane value.

4] Not all engines react the same way to blended fuels. Some users report excellent service and great engine life while others report reduced engine life in the form of stuck rings and excessive carbon.
This is why the process is considered experimental in each case.

5] As a rule, IDI engines are more forgiving than DI engines when burning WVO or Blends.

I can only offer my own experience with blending which admittedly was not run long enough to give useful info in the way of a teardown/inspection after 250 hrs..

Base stock: Filtered and dehydrated WVO
Acidity:      Low (Titration value of 1.5 to 2)
Blend:        70/30 WVO and Diesel fuel with 1 oz. of turpentine per gallon of mixed fuel
Engine:       Changfa S195
Combustion: Direct injection
Starting:      Excellent
Smoke:        Minimal (light white smoke for 1 minute until slightly warmed up)
Fuel Separation: None

I have had a 1 liter sample of this mix in a glass bottle for over 9 months.
-Still clear
-No separation of the constituents
-No apparent polymerization, gummy film, sticky residue.

Sorry that there is no conclusive internal engine inspection to report, however I thought the blend info and separation resistance of the fuel might be of some interest.
I do intend to keep running this fuel in my direct injected Listeroid.


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