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Hijet - motor swap???

Discussion in 'Introductions' started by TwoToolDesigns, Feb 14, 2024.

  1. TwoToolDesigns

    TwoToolDesigns New Member

    Hi friends!

    I recently acquired a Daihatsu Hijet and I'm in the process of determining its exact year of manufacture. The title indicates it's a 2000 model, but based on its appearance, I suspect it's a 1993 or older model.

    Currently, I'm dealing with some carburetor issues, as the previous owner replaced the original carb with aftermarket ones from Amazon or eBay. I've never been a fan of carburetors and would prefer fuel injection.

    Now, onto the exciting part...

    I have a 2003 Yamaha R6 that's been sitting in my side yard, and I'm considering swapping its engine into the Hijet. This swap would potentially double the horsepower and give the Hijet a more appealing sound.

    I've seen some YouTube videos of people swapping their Hijet engines with motorcycle engines around 1000cc. However, one common issue is the lack of reverse gear and potential interference with the truck bed space. Ideally, I want the truck bed to function normally and the swap to look as "stock" as possible.

    Goals:
    Increase reliability/speed
    Retain reverse/work truck functions

    Questions:

    1. Is it possible to connect the motorcycle engine/transmission to the existing Hijet transmission to retain the reverse gear? Would this setup function like a hi/low transmission? How would the gearing be affected?
    2. I haven't seen this type of swap done before. Is there a specific reason for this? Any input or advice would be greatly appreciated.

    I have some fabrication skills welding/Cnc plasma cutter/CNC router. I know this would require some fab work to make happen but I believe I could make it happen.

    I've attached a few pictures of my Hijet featuring my electric dirt bike for reference. Any feedback or suggestions on this project would be welcomed!
    IMG_7979.jpeg
    IMG_7982.jpeg
     

    Attached Files:

    Jonathon Carey likes this.
  2. Dewie

    Dewie Member

    I'm also new to these trucks but the following is what I've observed:

    The biggest reason we don't see a whole lot of swaps done in these trucks is the lack of space for your typical in-line multi-cylinder to lay, they're nearly horizontal in the truck and most engines are designed to stand more vertical (oil pumps etc are designed accordingly)

    This means they lend themselves to a Boxter engine (horizontally opposed) more easily - only the problem with that becomes that there isn't a ton of room between the frame rails either...

    I HAVE seen diesel VW engines retro-fitted to work in air-cooled VW vans, they have weirdo wedge shaped oil pans and different oil pick-ups to allow them to sit at the extreme angles so they fit.

    Then you'll get in to gearing. If you try to feed the motorcycle transmission in to the transmission for truck you'll have essentially a double reduction. You can potentially get around this if you keep the bike engine in high gear and feed that output in to the transmission of the truck. You'd need to figure out how to center the output of the bike engine to the input of the transmission and build an adaptor accordingly. Alternatively you might be able to build some sort of chain or belt drive between the two.

    There IS a few bike engine (And diesel engine) swaps out there that I've seen in my travels, though nothing that was super well documented that I've run across yet.
     
  3. ttc

    ttc Active Member

    look under the drivers seat for the build number that will tell you more.
     

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