Puppeteer

Author Topic: Injector heater/compression change over valve  (Read 8850 times)

spencer1885

  • Full Member
  • ***
  • Posts: 207
    • View Profile
Injector heater/compression change over valve
« on: October 14, 2010, 05:46:10 PM »
The injector heater failed the other week so I have been running with out it.
Every day before the next run I unscrew the cylinder head bung and scrape out any carbon that has collected.
There has been no difference in the amount of carbon and the injector tip is keeping fairly clean just as when the heater was working.
I thought I would refit the compression change over valve and see what difference running in low compression would make.
I can also report that there is less carbon build up.
I think the extra air turbulence is moving the carbon and the engine run's smoother in low compression.
Before I started running my Lister on wmo I read what people where saying about wmo and they would say you need extra injector heat and to run in high compression and run the engine under a heavy load.
I am finding you just need a 2000 watt load and a thermostat and that's it.
But I have had injector tips carbon up in the past but I think the waste oil I have at the moment is working well but I don't know why. 
All I know is it's working very well at the moment.
Matthew

Tom

  • Hero Member
  • *****
  • Posts: 1747
  • Green power is good.
    • View Profile
Re: Injector heater/compression change over valve
« Reply #1 on: October 14, 2010, 06:12:31 PM »
Very interesting! I'm wondering if the injector tip is fouled more by the ash content of some oils rather then carbon. The WHO I'm have runs great straight, however it fouls the injector tip fairly quickly with a white deposit that will sometimes build up 3/16" deposit along each injector stream. No external heat is used and no change over valve either. Perhaps I should get one and see if it makes a difference.
Tom
2004 Ashwamegh 6/1 #217 - ST5 just over 3k hours.

bschwartz

  • Sr. Member
  • ****
  • Posts: 322
    • View Profile
Re: Injector heater/compression change over valve
« Reply #2 on: October 14, 2010, 06:14:39 PM »
Thanks for your report!! †
It's always good to hear what is working, as well as what isn't.

What kind of injection heater were you using?
How are you filtering your WMO?
Just 2000 Watte?!?!? †On a 6/1, that's about 2/3 full load. †I'd expect that to work well. †I've seen the problems with
carbon build up (on WVO) seem to happen on 1000 watts or less load.
-Brett

1982 300SD, 1995 Suburban 6.5, 1994 F250, R170, Metro 6/ sold :( , Witte CD-12 ..... What else can I run on WVO?

spencer1885

  • Full Member
  • ***
  • Posts: 207
    • View Profile
Re: Injector heater/compression change over valve
« Reply #3 on: October 14, 2010, 06:47:10 PM »
I was using a ptc heater or I think that's what it is called.
I had it fitted to the side of the injector and it used to get really hot.
It just blow the fuse one day,I did replace the fuse but it blow straight away so I am sure it's stuffed.
I just use sock filters first and I also have two extra one micron water filters  on the engine plus the standard fuel filter.
I had thought that when the bung is remove the whiter the carbon deposits the better the burn.
When I have a fouled injector tip the carbon in the swirl chamber is never white but black.
I to have had a foul injector tip with white carbon along the injector stream more than a few times and this has caused the engine to not take it's load and use more fuel and run hotter and also smoke.
 I could be posting in a few months tell you another story but at the moment it seems to working well.
I have 1500 litres of this oil still to burn.

Tom

  • Hero Member
  • *****
  • Posts: 1747
  • Green power is good.
    • View Profile
Re: Injector heater/compression change over valve
« Reply #4 on: October 14, 2010, 07:18:29 PM »
Even more interesting, you've seen both black and white deposits. It seems the differences must be the fuel.
Tom
2004 Ashwamegh 6/1 #217 - ST5 just over 3k hours.

spencer1885

  • Full Member
  • ***
  • Posts: 207
    • View Profile
Re: Injector heater/compression change over valve
« Reply #5 on: October 14, 2010, 07:42:51 PM »
My only thought was the white ash was normal when burning wmo because when my waste oil fired workshop heater is burning cleanly it has lots of white ash.
When it's not been burning cleanly it is sooty and black with no white ash.
I think the higher the ratio of waste oil burnt in a diesel engine the more white ash you will see if its burning it correctly.
I have notice if I just run on diesel the swirl camber is black.
This is why I feel that the engine has been running well when I see white or grey soot in the swirl chamber but I could be wrong.

Bottleveg

  • Full Member
  • ***
  • Posts: 246
    • View Profile
Re: Injector heater/compression change over valve
« Reply #6 on: October 15, 2010, 01:26:39 AM »
My only thought was the white ash was normal when burning wmo because when my waste oil fired workshop heater is burning cleanly it has lots of white ash.
When it's not been burning cleanly it is sooty and black with no white ash.
I think the higher the ratio of waste oil burnt in a diesel engine the more white ash you will see if its burning it correctly.
I have notice if I just run on diesel the swirl camber is black.
This is why I feel that the engine has been running well when I see white or grey soot in the swirl chamber but I could be wrong.


This is what I find with my wmo central heating burner. White ash and all is well. Black ash and itís time to clean the burner box.

toydiesel01

  • Full Member
  • ***
  • Posts: 101
    • View Profile
Re: Injector heater/compression change over valve
« Reply #7 on: October 15, 2010, 01:31:59 AM »
I have tryed who and mixed in some wmo mixed 50% diesel and saw no difference .  But i don't have that many hours on it yet. Maybe 30 hrs

spencer1885

  • Full Member
  • ***
  • Posts: 207
    • View Profile
Re: Injector heater/compression change over valve
« Reply #8 on: October 15, 2010, 04:52:55 PM »
You will not see any difference in the carbon at a 50% mix.
If you increase the amount of oil to 75% plus you will see the swirl camber has white ash in it.
 ;)