Unconfigured Ad Widget

Collapse

Announcement

Collapse
No announcement yet.

Retarding Injection Timing for Biodiesel

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Retarding Injection Timing for Biodiesel

    Seems to me that every test ever done using biodiesel is done in a completely unmodified engine, tuned to run on petroleum distillate. I have heard that NOx emissions are slightly higher in this case and also obviously there is a performance and fuel economy hit as well.
    I have also heard that by retarding the timing of the injection, to better suit the slower combustion properties of biodiesel, the performance can be improved, as well as the NOx reduced.
    If this is true, I am baffled that so many studies and trials are done without properly tuning the engines. This issue has been mentioned before in this forum.
    Has anyone got any real info on this subject, can anyone confirm performance improvements or has anyone seen any decent reports published on emissions testing when properly tuned for biodiesel?
    I've been considering getting one of these devices fitted, as they claim to provide an easy way to change the injector timing on a diesel engine and do it digitally without interfering with the vehicles ECM. It can also be easily adjusted or disabled. Sounds to me like the perfect way to test it properly, the only thing missing after that would be a dyno and an exhaust gas analyser. I have also written to the company asking them to confirm the use of their product with biodiesel, but have thus far been ignored. Feel free to ask them the same question and let us know if you hear back.
    I think that if this sort of think is reasonably cheap and easy, we should all be looking at ways to better tune our vehicles for biodiesel.
    I remember many years ago when I used to install LPG conversions (for a hobby), while it was possible to run LPG with the same timing as petrol, it was so much better to run it at a timing best suited for the fuel (in this case between 10-18° advanced). Why do people not apply the same ideas to biodiesel?
    Robert.
    Site Admin.

  • #2
    Re: Retarding Injection Timing for Biodiesel

    Hi Rob,

    boy you had a busy night. I agree with your point that people should be testing with properly tuned engines, but once we start "modifying" stock setups people might be less inclined to try or use it if they think that they have to tinker with their timing. I'm sure its probably not a hard thing to do but once you cross that threshold it may turn people off it. Although people dont mind "tuning" their engine to run better on LPG. But for the masses I guess they will be happy to not play with around with timing if they dont have to. Also are there any references to power gain/loss from retarding timing.
    Last edited by joe; 21 June 2006, 12:47 PM.
    Joe Morgan
    Brisbane Biodiesel Site Admin
    http://www.brisbanebiodiesel.com

    Searching tips using Google - SVO Dual tank systems
    SVO, Common Rail and Direct Injection - Vehicles converted to Used Cooking Oil

    Comment


    • #3
      Re: Retarding Injection Timing for Biodiesel

      Robert, over the years I have developed a 'feel' for engine performance (I used to build race engines). Biodiesel has a bit quicker burning rate than dino diesel. It is not much, but if you engine is already a bit advanced, then it will be too far advanced for B100.

      I use a method where I get the feel of the injector timing with dino diesel. I set the timing so it is just a tad retarded, not enough to make a significant change in performance, just enough that I know it is not peaking in pressure before top dead centre.

      Another way is to see how the engine runs when it is cold. If the engine is slightly sluggish when cold at part throttle, but improves with the warming of the engine, then the timing is about right. If engine is 'perkier' when it is cold at part throttle and then loses a bit as it warms up, then it is too far advanced.

      I set my timing so that it is a bit retarded on dinodiesel and slightly advanced on B100. That way no matter what I run, and especially if there is a mixture in the tank, the timing is in the ball park.

      Comment

      Working...
      X