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Thread: Greener combustion...?

  1. #1

    Greener combustion...?

    A new greener internal combustion engine...

    http://www.zajacmotors.com/
    SI VIS PACEM PARABELLUM

  2. #2

    Re: Greener combustion...?

    interesting find. what's even more interesting is that it appears to be something you can deploy rather quickly to an existing technology.

    wonder if this will all work in real life in a production vehicle on a mass produced machine.
    Lance
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  3. #3

    Re: Greener combustion...?

    wow... very neat concept and seems like it would be very easy to implement!
    -andy

  4. #4

    Re: Greener combustion...?

    http://www.zajacmotors.com/the-zajac...-by-step.phtml

    It is a neat idea, but I can see more than a few problems with their idea
    - increased frictional loss through the need for an extra crank, conn rod and piston
    - "In the power and exhaust cylinder, the Zajac engineç—´ power stroke is longer and can be as much as 220% that of a standard engine." how is that even possible? the spark plug in a "normal" enigne is lit off BTC so that by the time the gasses start to expand (the flame front takes a few mS to get working) the piston should be ~10* ATDC, any sooner and the piston is pushing straight down on the conn rod and crank or the crank is pushed backwards(there needs to be ATDC offset to turn the crank).
    - in their diagram, they are using "rotary valves" which have been around for decades, not the standard poppet valve that we all know. Rotary valves have worked for short periods of time in engines but have inherent flaws with sealing and the "dead space" within the shaft (which works as a shock absorber, if you will, slowing down gas flow through the shaft)


    ehh, I'll stop here . . . I'm usually in a foul mood in the morning, maybe I'm just tearing it apart because I haven't had my coffee, maybe their explanation is missing a critical element that would tie it together better. But then again, have you guys ever heard that back in the day they made an carbureted engine that ran on water . . . Until I see a running prototype, it's just a theory and an idea
    Keith '88 4runner SR5 Garage Thread

  5. #5

    Re: Greener combustion...?

    I think, coarx, what they mean about it having a longer power stroke is that the pressurized gasses are forcing the piston down for its entire travel rather than a just an explosion at the top of its stroke. In a typical gasoline engine, you get a the flame front, a bang, and then the pressurized gas forces the cylinder through the rest of its stroke. Thats one reason in theory why a diesel engine is more efficient than a gasoline engine. The diesel fuel is injected directly into the cylinder, over more degrees of crank rotation, keeping an even push on the piston.
    I imagine the rotary valves were just for the convenience of the illustration. As the flash animation shows poppet valves. Or maybe they plan on using rotary valves, I would hope not.

    One thing I was wondering about is how the combustion chamber will contain the immence pressure created by burning fuel. On a diesel engine, BEFORE combustion, the pressures area in excess of 500psi, imagine what it is after combustion at full throttle.
    Also, with fuel combusting in the chamber and the immense pressure it creates, wouldn't it be hard for the compression cylinders to overcome that pressure and force fresh air into the chamber.

    Pretty neat idea though, I really want to see one actually run.
    &#039;81 pickup, longbed bobbed short, 35&quot; Yoko&#039;s and tons of other goodies. 4.7 gear T-case. NEW: 20r/22r hybrid motor!<br /><br /><br />I done ran into my baby and finally found my old blue jean<br />Well, I could tell that they was mine from the oil and the gasoline

  6. #6

    Re: Greener combustion...?

    Very interesting indeed. Works a lot like a turbine but with pistons instead of fan blades.

    Judging by the uses they suggest, this is more of a steady state machine much like a turbine but with better transient response and probably faster warm up. It would be good for stationary generation or maybe in a range extended electric vehicle where the engine tends to stick to one RPM.

    It will be interesting to see how light they can get this. I'd put the combustion chamber directly into the block but they show it on top. Block is strong, on top would have better insulation. However, if it was attached the part of the block that had the power/exhaust cylinders they could take advantage of that waste heat.

    Frank
    1985 FJ-60, 3FE, Hell Creek lift, 2009 H3 sold

  7. #7

    Re: Greener combustion...?

    cool

    i thought it was this type of 'green'...http://www.hemphasis.net/Fuel-Energy/fuel.htm
    [quote author=Euphorickaty80 link=topic=575.msg3747#msg3747 date=1175627780]<br />I was alot of fun to build.[/quote]

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