K-Cycle or Christianson Engine

Discussion in 'Gas Engines' started by Submarine Tom, Aug 20, 2009.

  1. Submarine Tom

    Submarine Tom Previous Member

    I attended a lecture by Dr. Christianson (SP?) in 1983 at Tech. school in

    Calgary, Alberta, Canada promoting the K-Cycle Engine. It was developed

    for a few years and then appeared to have died. It was a crazy idea but

    resulted in much higher efficiencies than conventional internal combustion

    engines. Cylindrical in form, the cylinders rotated like a "six shooter". The

    pistons were opposed while the connecting rods travelled on a roller coater

    looking guide simulating a variable radius crankshaft. Really hard to

    discribe, but I am curious if anyone has heard anything more current about

    the design.

    Last edited: Aug 20, 2009
  2. Redtick
    Joined: Jul 2009
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    Redtick Junior Member

  3. marshmat
    Joined: Apr 2005
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    Location: Ontario

    marshmat Senior Member


    I know the engine you're talking about- I haven't seen it personally, but a friend of a family member worked on a version of it (in Manitoba, I think), way back in the '70s.

    The essence of the concept was reincarnated as the "OX2" in the mid-90s. It then vanished for a few years, and is now back in the news (see http://www.ox2engine.com ).

    There's nothing particularly complex about the way it works; thermodynamically, it's a pretty standard four-stroke engine. What makes the thing so interesting is the strange, strange way that the engineers decided to package it- an unusual circular shape with axial pistons in a rotating engine block, and a roller-coaster-like fixed cam ring in place of a crankshaft.

    This unorthodox geometry offers a few advantages: among them, a non-sinusoidal piston motion (thus extended dwell time, better control of combustion, improved efficiency), excellent intake and exhaust port flow, and the ability to fire each piston more than once per revolution. All told, the thing was giving dyno results in 1996 that were roughly on par with a stock GM 350ci small-block, despite weighing only 125 lb / 57 kg. I wouldn't be surprised if they've got the output up even higher now.

    It ought to be fairly easy and cheap to build, too- there are only a handful of parts, most of which can be made with a standard lathe and mill.

    From what I understand, the main problems were with sealing (similar issues to the early Wankels- I'm told the OX2 guys came up with some kind of full-floating port seal to fix this), raising capital, and getting it into production. Car companies, by and large, prefer to do their engineering in-house, and tend to be reluctant to embrace anything outside of what they're already familiar with.
  4. Submarine Tom

    Submarine Tom Previous Member


    That's the one! Interesting indeed. I'll check out the sites.

    Thanks, Tom

  5. Submarine Tom

    Submarine Tom Previous Member



    Wow, has the design ever changed. It looks like they dumped the opposed pistons,

    they used to move towards each other, creating the compression chamber between them.

    The clean cylindrical shape is gone too. It sure made a lot of sense to a bright eyed, college kid

    in 1983 but it would certainly be tough to brake into the traditional internal combustion engine market.

    Thank you again for recognizing my query. I've looked many times over the years for info

    and always came up dry.

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