Injector Nozzles

Discussion in '6.5 Performance' started by 6.2 turbo, Dec 18, 2011.

  1. 6.2 turbo

    6.2 turbo Active Member

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    I tested quiet a few used injectors,and nozzles. Pretty much all of them leak. Some the pintles were also stuck. Lapping the needles with polish has debatable results . I used to think a little leak at the tip was ok,since they almost all do this. I have since changed my mind,and think it might be the number one cause of engine failure. Brand new china marine nozzles will also leak. It seems new Bosch nozzles are kinda rare,and Bosch marine nozzles even more rare. I thought that the main difference between the 304 turbo nozzle and the 311 marine nozzle was just the cut off tip. This is not the main difference,the marine nozzle has .010 more travel. Hole sizes are also identical. I believe the extended tip on the turbo nozzles is just there in case of carbon build up,it will not really restrict fuel. The gap between the needle and seat,and also the flat side of the pintle,limit the amount of fuel. For now I'm going to probably use some new stock injectors. Later I want to either increase the travel on 304 nozzles,or get some Monark or Bosio nozzles for Mercedes and VW applications. Does any one know if they would fit ? If not I will just buy one and check it out . I also believe that the reason people have trouble with marine injectors,is probably the nozzles are poor quality,and leak,or the tips carbon up ,because of the shortened needle tip.
     
  2. 6.2 turbo

    6.2 turbo Active Member

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    I bought a used Mercedes injector. Very interesting nozzle,it has holes in the needle. The nozzles will only fit in 6.2 long body housings. I pop tested it and it seemed to have more of a finer mist,than a 6.5 nozzle. It also has .040 of travel in the pintle. A stock 304 nozzle has .025 and the 311 marine has .035 travel. Instead of two nozzle options I will now have a lot more. Any VW or Mercedes nozzle will fit.
     
  3. 4thesporty

    4thesporty New Member

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    Having been playing with diesel mercedes for about 10 years I know a little about their injectors.

    You should look at the Monark brand injectors for the OM617 motors. Very good stuff. Night and day with my genuine Bosch (germany, not India) ones.
     
  4. 6.2 turbo

    6.2 turbo Active Member

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    I think I narrowed it down to a dnosd 265 or 314. I would like to go with Monark. The stock Mercedes nozzle that I have is a dnosd 240. I'm not positive a higher number always means more flow. It does look like the 265 and 314 are flat sided like a 6.5 turbo nozzle.
     
  5. great white

    great white Active Member

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    Very interesting.

    Sub'd.
     
  6. 3500GMC

    3500GMC Stand Your Ground

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    Yep short inj, short nozzle, long, long...

    Interesting and thought provoking.. :D

    I think the reason I have to crank timing is because I'm trying to push too much fuel through the std Bosch 6.2 long nozzles...It's like the spray duration is too long. I need to fix this...
     
  7. turbonator

    turbonator New Member

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    Another good thread, will be keeping an eye on it for sure..... great info you guys...
     
  8. Turbine Doc

    Turbine Doc Just Another Diesel Guy

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    IIRC Kennedy's h/o nozzles used Mercedes tips on GM injector bodies I don't know which tips he used I need to go out to my shop & see if I still have a set out there with those tips on em.
     
  9. turbonator

    turbonator New Member

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    Well, once again, we see that we are not inventing the wheel, just seeing how it turns....LOL. Would be interesting to see what were used in the H/O nozzles.
     
  10. Burning oil

    Burning oil LeroyDiesel.com

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    Very interesting, looking forward to more info.
     
  11. great white

    great white Active Member

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    Waiting........


    ;)
     
  12. 6.2 turbo

    6.2 turbo Active Member

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    I ordered a dnosd 261 Monarch from Mercedessource. It was the only one they sell individually. I got a set of 8 long body 6.2 injectors,and 2 more Mercedes injectors ,at the junk yard. The 6.2 injectors are USA Bosch,the nozzles are dnosd 248. They also have a long travel of .040. I know from experience that these nozzles don't make any power with a turbo .
     
  13. Cumminsfever

    Cumminsfever Been there, broke that.

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    Gotta follow this.

    A bit of my own scratching around revealed a mercedes nozzel does fit the standard 6.5 body with a bit of lathe time, and it seems to have potential, but also doesn't move as much fuel as the 6.5 nozzel.

    Where are y'all setting your pop pressures?
     
  14. 6.2 turbo

    6.2 turbo Active Member

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    I was going to go with 2500 psi. But I might go lower to get full pintle travel ? The 304 nozzle would probably be the best one for high pop pressure,since it has very little travel. The dnosd 240 Mercedes needle has a .005 hole in the tip,and .010 hole across the tip. It is supposed to create a pilot injection. I seriously thought about trying a used set of these. I already have 3,and know were to find more.
     
  15. L98TPI

    L98TPI New Member

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    Seems to me, proportionally OM617 nozzles are to small for a 6.5. An 8 cyl version of a OM617 would be 4.8 liters. The spray patten may not be optimum for the 6.5's chambers also.

    Will a smaller nozzle cause a higher peak back pressure on the pump? Increase the time it will take to get the whole fuel dose in at wot? Limit the max rpm or power? :dunno:
     
  16. 6.2 turbo

    6.2 turbo Active Member

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    I'm not sure if they will be smaller,and hopefully they open farther than the dnosd 304. Also the pintle must be restrictive,or it wont really lift at all .
     
  17. 6.2 turbo

    6.2 turbo Active Member

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    I got a Monark dnosd 261,it has .035 of plunger travel. The tip is very similar to a dnosd 304 . When pop testing it gives longer pulses,it will not chatter on it's own,like stock injectors do. Different pop pressures do not change this. Also it will dump 100 psi of fuel with each pop,stock injectors will drop a max of 50 psi. I decided to give them a try and ordered a 10 pack,since they are on sale,and won't hurt to have some spares. I also tested a dnosd 273 VW nozzle,they have a very small flat on the pintle,and spray with a very narrow pattern. It did chatter though. The Monark spray pattern is slightly narrower than stock.
     
  18. sshewins

    sshewins Jesus Freak

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    Keep us posted. Very interesting stuff here
     
  19. turbonator

    turbonator New Member

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    The longer pulse and the greater pressure drop, both indicate more fuel per pop. This is a good news indeed.....:thumbsup:
     
  20. sshewins

    sshewins Jesus Freak

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    Now would you set the 'pop' pressure at 2250 on these monark's? Or is 2250 for gm units?
     

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