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Hercules Diesel Swap

Discussion in 'Projects' started by Air2Mud, Sep 5, 2013.

  1. Air2Mud

    Air2Mud New Member

    Sep 5, 2013
    Hey Y'all,

    A White/Hercules DD298ER, 6Cyl, 3.9L diesel came into my possession and I am pretty dang interested in putting it into my truck. Now, this particular motor was part of a military generator set, however I have seen a very little bit of information stating that this model was also used to push a tractor as well (c. 1950's).

    I'm wondering if any of you have experience with this engine, or know of any suitable automobile applications.

    Thanks for your time,


    Attached Files:

  2. smokinmad

    smokinmad Supporting Member

    Dec 24, 2013

    That looks more like Turquoise to me, not White. LOL I know smart-butt, my wife would agree.lol Ok Seriously, check these ole retarded, ooppss, Retired farmers out,http://shadetreeconversions.com/. They even put a 3 cyl. diesel in a Mustang. If anyone can help, They can.
    Good Luck

  3. pogobill

    pogobill Registered User Staff Member

    Jan 31, 2012
    Hello Air2Mud, nice looking unit! Must be some way to fit that into a truck. I'd love to have it.... I have a '47 Diamond T 509 with a Hercules 6 cyl gas engine in it. Do some research and I'm sure you can find the info that you need. I do believe I've heard the same thing abut these engines being used in early '50s tractors as well and set up for generating power.
  4. Mickey

    Mickey New Member

    Aug 14, 2010
    A couple things to consider. First, the Gov, in a generator application the gov was set to hold a constant speed, possible 1800 rpm. How would you address this in a vehicle that requires various speeds and changing speed quite often? Second item, what is the max speed of the engine and with present gearing in the truck, would the ground speed be adequate? What's the availability of differential gear sets to increase ground speed if needed?

    Engine sure looks nice and clean. Did you put the fresh coat of paint on it or was it already looking pretty?

    Another thing to think about with the cost of diesel fuel what it is today, would this engine swap be economically viable in a reasonable amount of time?
  5. smokinmad

    smokinmad Supporting Member

    Dec 24, 2013
    I once saw a Big Ole Dozer. had a bad motor, so they replaced it, with a 4cyl. pick-up engine. Yep, kewlest thing I ever did see's. Yeppers, put the 4cyl. and the 4sp. tranny, in where the old engine was, hooked the truck tranny to the dozer tranny. The truck tranny kept the rpm's of the 4cyl. high enough to run that huge dozer. Honest to Goodness. Its not about the Horse Power, its all to do with the Gearing.
  6. Cublover

    Cublover Well-Known Member

    Feb 20, 2011
    I saw a track hoe with a slant 6 Chrysler on the back. It stuck out past the side, since it was a former 3 cyl diesel.
    I agree with Mickey about the possible drawbacks and fuel costs.
    However, If you are building a 'toy', fuel costs don't really figure in anyway.
  7. smokinmad

    smokinmad Supporting Member

    Dec 24, 2013
    Fuel Costs!.??! If ya went to the link in my 1st reply, Shadetree conversions, you would have to agree with them. When I mow the yard (3 acres) with a gas engine I have to fill up twice, thats 3 tanks of gas. However, with my diesel tractor, I mow that 3 acres twice. Honest to goodness, oh the tractor has a Bigger Tank. NOPE. My diesel chevy suburban got 25 mpg all the time, my gas van, 17 tops. two tractors working the fields, the guy on the gas tractor fills up at lunch, the guy on the Diesel,also, the next day. Diesels get far better economy than a gas, Unless you start chipping them and turning them up for POWER. Ask all these kids with their black smoking big diesel trucks. Should have left them alone little truck driver with your big truck stacks in your beds. You need a C.D.L. to be a truck driver son.....OOOPPPSSSSS Sorry, Almost lost it there. LOL I'M BACK......Ya'll have a good day, I better go play in all this snow were getting in Illinois, here I come Johnnie, warm up those Glow Plugs.
  8. Cublover

    Cublover Well-Known Member

    Feb 20, 2011
    I never understood the concept of cutting a hole in a perfectly good bed floor and putting bigger pipes than I use on my wood stove 'in the way' of actually hauling stuff?? Another thing that I question. WHY pay $50,000 for a truck, then take it out and beat it to crap in a couple years? Mudding, rock crawling, etc.
    I have nephews that do that sort of thing. They use a truck that they BUILT to do that. The hauler is a black, clean, shiny, F-350 crew cab that never goes in the mud or woods.
    Getting back to the original post though..
    GO for IT! Stick that big diesel where you want it and figure it out as you go!
  9. ErnieS

    ErnieS Country Biker

    Jun 1, 2011
    Does anyone know who Onan got their diesels from that they used in their 10K class marine generators in the 80's?