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Gear oil as fuel

Discussion in '6.9L IH & 7.3L IDI Diesels' started by Daniel McCurdy, Feb 24, 2021.

  1. Black dawg

    Black dawg Registered User

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    On 6.9-7.3 injectors I have never seen any real deposits on the injector.......regardless of fuel.


    Always shows up in the rings though......
     
  2. Isaac Ristow

    Isaac Ristow Full Access Member

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    Don't do it its puts allot of deposits in the combustion chamber and that oil is probably pretty spendy I would save it or try to sell it, Sounds like some of the oils we use in the roller cone and jaw crushers and screen decks here in the gravel pit and that shit is very expensive
     
  3. leswhitt

    leswhitt Full Access Member

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    Can you expand on that? What deposits were you seeing in the combustion chamber and what oil were you running?
     
  4. Isaac Ristow

    Isaac Ristow Full Access Member

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    I've never ran gear oil in a idi but I do know that all the friction modifiers and additives in the gear oil doesn't burn right its not made to burn its made to handle extreme pressures and temperatures. I'm not saying your truck won't run on it but all the stuff in the gear oil that doesn't burn is going to deposit and gum the rings and all that up
     
  5. leswhitt

    leswhitt Full Access Member

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    I'm at just shy of 60k miles on waste oils in my IDI and the fuel savings have paid for a new engine several times over. I haven't had to pull the head yet but have looked through the injector bore and haven't seen anything abnormal. This is ATF, motor oil, gear oil, transformer oil, hydraulic oil....basically anything petroleum based has gone through my truck.

    I dispute your assertion about gumming up of the rings since I haven't seen increased oil usage, extra smoke, lost power, or any of the usual side effects of bad rings. Maybe someday I'll have reason to pull the heads and can get a definitive look at what, if anything, the WMO has done.

    If the mix isn't burning right, you'll get extra smoke which is incomplete combustion. The pressure inside the cylinder blows everything unburned out the exhaust. I just don't see how the modifiers can resist the heat, not even smolder, and hang on inside the cylinder and not get blown out.
     
  6. Black dawg

    Black dawg Registered User

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    Basically any oil, will leave hard white deposits. Have seen it in the hole in the pre chambers, and builds up on top of the piston and some in the rings. THis is over 5 different engines burning wmo filtered well and burned basically smokeless and odorless.
     
  7. leswhitt

    leswhitt Full Access Member

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    I've never experienced that and I've also almost never experienced odorless wmo burning. Are you the one burning it or someone else?
     
  8. Black dawg

    Black dawg Registered User

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    1 7.3 idi around 150k of 50/50 diesel/filtered wmo. Started and stopped on straight #2
    1 6.5 mechanical pump turbo engine around 50k of same mix, single tank so always on mix. Engine never showed any signs of ring issues.....never had it apart. It would have the hard white stuff build up on the end of the injector, seems like every 10k or so i was pulling them out and chipping the stuff off.
    1 7.3 idi probably about 25k same setup as first truck.
    1 7.3 idi about 100k


    the first three were mine, all three 7.3 motors and a 7.3 ps motor that I didnt list all slowly lost compression. Two of them were taken apart and found stuck rings with the hard white stuff built up in the ring lands.

    The first 7.3 is still running, but uses lots of oil and has low compression.

    These were all pulling trailers(except the 6.5), always figured that working them would keep anything from building up.


    And I agree on the money saved on fuel making it worth it, it just isnt as free as a lot of guys make it out to be.
     
  9. Black dawg

    Black dawg Registered User

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    And yes, warmed up never really had any kind of smell......at 50/50.....thicker mixes or straight are noticeable
     
  10. IDIBRONCO

    IDIBRONCO IDIBRONCO

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    These engines can be run on a lot of different types of oils for fuel. The above is why I'll just stick to plain, old fashioned dino fuel, despite the cost. I just don't want to mess with the possible outcomes of other types of fuels. I have seen the white deposits by the pre cup holes and on top of pistons in a few engines. I had no idea what caused it before.
     
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  11. TNBrett

    TNBrett Full Access Member

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    Why not just sell it and buy diesel. If you sell a 5gal pail for $30 you can buy 10 gallons of fuel.


    Sent from my iPhone using Tapatalk
     
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  12. IDIBRONCO

    IDIBRONCO IDIBRONCO

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    Or just keep it and use it for gear oil.
     
  13. Farmer Rock

    Farmer Rock just a fella' without a 10mm socket

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    My thoughts exactly!




    Rock
     
  14. The_Josh_Bear

    The_Josh_Bear Full Access Member

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    It would take me the rest of my life to go through 5 gallons of gear oil! Lol. My pickup is the only thing that uses standard gear oil in my "fleet". :)
     
  15. TNBrett

    TNBrett Full Access Member

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