Diesel engine and propane

Discussion in 'Diesel Engines' started by rubenova, Sep 12, 2022.

  1. rubenova
    Joined: Aug 2011
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    Location: Fidalgo Island, WA

    rubenova Junior Member

    I bought a Champion 3400 watt dual-fuel inverter / generator that I run on propane. I liked the variable speed feature for lower noise, wear and fuel consumption, and the propane for not gumming up with gasoline. Naturally, less than a year later I found something better. Hatz has something similar but diesel and with the option of AC or DC. My question: is there a way to add a measured amount of propane to a diesel generator to reduce diesel consumption? I would think propane would keep the engine oil cleaner and possibly help keep wet stacking / fouling down as well as being cheaper fuel. Maybe this is already being done and my google skills are lacking.

    Thoughts?
     
  2. Rumars
    Joined: Mar 2013
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    Rumars Senior Member

    Yes it's already beeing done, search for "diesel LPG conversion". It's not a cheap thing to do, if the manufacturer doesn't offer it as an option I doubt it's economical for a small generator. The kits are specific to the injection type used and have to be installed and calibrated by schooled personnel.
     
  3. fallguy
    Joined: Dec 2016
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    fallguy Senior Member

    Isn't he asking if mixing diesel and lpg is a thing? Sounds insane to me.
     
  4. Lepke
    Joined: Sep 2015
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    Lepke Junior Member

    You might look into methane production from cow manure. Places with lots of cows use the methane to run a generator. I had a dairy and looked into it years ago. There was a guy in South Africa that used a diesel he added spark plugs in place of the injectors and a propane carburetor.
     
  5. Rumars
    Joined: Mar 2013
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    Rumars Senior Member

    No, that's precisely the way it's done, even the big purpose buildt CNG engines still require diesel fuel for the ignition (called pilot jet ignition). If the engine is not purpose buildt for gas fuel only a portion of the diesel can be replaced. The gas side is a multipoint manifold injection as used on petrol conversions, the problems are in convincing the diesel injection to inject proportionately less fuel. Electronically controlled engines are easier then mechanical ones in this respect.
     
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  6. comfisherman
    Joined: Apr 2009
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    Location: Alaska

    comfisherman Senior Member

    I dunno the inns and outs of it as a sole fuel, but pre 2008 diesel standards the hillbillies I knew propane injected their tractor pull trucks on the weekends. Insane was seeing crewcab diesel run past pretty built street cars.
     
  7. rubenova
    Joined: Aug 2011
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    Location: Fidalgo Island, WA

    rubenova Junior Member

    The 3400 turns out to be a little large for my application if the water heater is turned off. My idea for the diesel would be to add propane, before plugging in a load, to raise rpm slightly for a cleaner burn. Then when plugged in and house loads cycle the generator would adjust the diesel as before. I'm not very familiar with LPG. I do know leaning out gasoline raises temperatures and eventually to pre-ignition. If there is a minimum air/LPG ratio, I'll have to think of something else.
     
  8. Rumars
    Joined: Mar 2013
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    Rumars Senior Member

    It would not reduce diesel consumption or make it burn cleaner, it would just increase the engines power (as exemplified by post #6). All you will achive is burning out the generating head or the electronics.
     
  9. rubenova
    Joined: Aug 2011
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    rubenova Junior Member

    I've found the lifted pickup crowd are running about 4:1 diesel to LPG on the dyno pulls. I would be nowhere near that, just a trickle to raise the no-load rpm. Looks like I'll have to rent a moving truck to experiment on...just kidding.
     

  10. philSweet
    Joined: May 2008
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    Location: Beaufort, SC and H'ville, NC

    philSweet Senior Member

    No, you mix the propane with the air, generally using a liquid propane fuel injector. Most add-ons are throttle body set-ups. For Bigger Engines like Class 8, It's multipoint injection into a custom adaptor plate. Automotive kits run about $6,000 for the engine side and double that for the fuel tank and fuel control system. That's a fleet price if you want 50 of them. A friend of mine is booked three years out now, mostly with utility company fleet vehicles. Class 8 straight CNG monofuel conversions run about +$45K out the factory (Cummins).

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