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Thread: The Bucket Foundry

  1. #4381
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    Always felt transfers were over rated.
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  2. #4382
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    My two new high tech fuel air mixing devices have just arrived, thankyou Rob. Humm, no manual, Ill have to try and remember how they work��, no more click of a button on the key board unfortunately.
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  3. #4383
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    Previously two steps forward, now one step back? -....... still progress!
    Wot! ..... no transfers? - that's preposterous!
    Strokers Galore!

  4. #4384
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    Quote Originally Posted by Flettner View Post
    So long worthless reed block housing.
    Quote Originally Posted by Flettner View Post
    Always felt transfers were over rated.
    Quote Originally Posted by Flettner View Post
    My two new high tech fuel air mixing devices
    The Zen path to Simplicity...just keep eliminating all the unnecessarily complex things in your life. .

    Cheers, Daryl.

  5. #4385
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    Quote Originally Posted by OopsClunkThud View Post
    since there is no head to squish against how about shaping the piston to squish the middle and the combustion in a torus. this gives a wall to place one or more spark plugs.

    Attachment 344102
    This was sort of the layout of my original Uniflow, two domed pistons against each other. Each cylinder was 50cc, each piston displaced 25cc, with a single spark plug per cylinder. I needed 40 degrees advance to get any sort of power out of it. So I fitted two sparkplugs per cylinder ( four altogether) , advance down to 20 degrees, more sensible but still a lot.
    Some of this is to do with how the scavenge is done.

  6. #4386
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    Quote Originally Posted by Pursang View Post
    The Zen path to Simplicity...just keep eliminating all the unnecessarily complex things in your life. .

    Cheers, Daryl.
    Yes, unfortunately, in my workshop days I met and had to deal with quite a few apprentices like that who liked the Zen philosophy (combined with the green stuff) and I saw two very expensive CNC machines bite the dust because of that simplicity!!
    Strokers Galore!

  7. #4387
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    Quote Originally Posted by Flettner View Post
    This was sort of the layout of my original Uniflow, two domed pistons against each other. Each cylinder was 50cc, each piston displaced 25cc, with a single spark plug per cylinder. I needed 40 degrees advance to get any sort of power out of it. So I fitted two sparkplugs per cylinder ( four altogether) , advance down to 20 degrees, more sensible but still a lot.
    Some of this is to do with how the scavenge is done.
    What bore/ stroke ratio did you use in that engine? and were both crankcases used to scavenge just one cylinder? - were the crankshafts turning in the same direction or contra rotating? - which arrangement would have been best? (ie from the point of view of vibration).
    Strokers Galore!

  8. #4388
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    I did consider casting a piston with what would amount to a surface fire plug in its center. Wires were to be cast in (ceramic coating) that went to the outside of the piston. Carbon 'slip rings' were to transfer the spark energy.
    All got too hard so I gave up. The differential piston size bought the combustion chamber to more managable dimensions with side spark plugs.
    My new design is back to same size cylinders and a far more cunning piston / combustion chamber layout. It gets rid of the traditional Uniflow transfer issues and makes for a handy combustion chamber. The guy in Italy is evaluating it, so I can't say nothing about it at the moment.

    Will, first engine, same direction cranks ( three gears), second engine opposite direction (four gears) all engines were smooth. Largely stuck to about square bore and stroke ( ish ). Exhaust lead intake by 6 degrees, exhaust and transfer were similar durations as a normal twostroke.
    This helped with blowdown.

  9. #4389
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    Quote Originally Posted by Flettner View Post
    .......... My new design is back to same size cylinders and a far more cunning piston / combustion chamber layout. It gets rid of the traditional Uniflow transfer issues and makes for a handy combustion chamber. The guy in Italy is evaluating it, so I can't say nothing about it at the moment.

    Will, first engine, same direction cranks ( three gears), second engine opposite direction (four gears) all engines were smooth. Largely stuck to about square bore and stroke ( ish ). Exhaust lead intake by 6 degrees, exhaust and transfer were similar durations as a normal twostroke.
    This helped with blowdown.
    Thanks, I have been wanting to ask these questions for a while - now I've been told, it clears up a few things - but what to do (or maybe just think ) next is the question - however ....... it's all progress as far as I'm concerned!
    Strokers Galore!

  10. #4390
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    Quote Originally Posted by Flettner View Post
    Always felt transfers were over rated.
    Yep, gotta agree. Used Devcon to block the top of the passages through to the cylinder ports. Seemed to expand a bit under running temps. Will grind it back a bit.

    Click image for larger version. 

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    "Success is the ability to go from one failure to another with no loss of enthusiasm.”

  11. #4391
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    Not casting related, but given the interest in moving sleeve engines in this thread: https://www.youtube.com/watch?v=I5m7HFtHLtQ

  12. #4392
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    Quote Originally Posted by speedpro View Post
    Not casting related, but given the interest in moving sleeve engines in this thread: https://www.youtube.com/watch?v=I5m7HFtHLtQ
    Ken,those were very interesting little engines intended mostly for model aircraft but despite that they didn't "take off" - dunno why, maybe too pricey but I did hear someone mention that the bevel gear was bloody noisy!
    Strokers Galore!

  13. #4393
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  14. #4394
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    Quote Originally Posted by Frits Overmars View Post
    Quote of the decade
    "It’s reasonably obvious that if you are going to pump that piston up and down, you might as well get work out of it every time the piston comes down rather than every other time the piston comes down,"
    Pat Symonds, chief technical officer of Formula 1.
    Quote Originally Posted by Katman View Post
    I reminder distinctly .




    Kinky is using a feather. Perverted is using the whole chicken

  15. #4395
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    Quote Originally Posted by husaberg View Post
    Quote of the decade
    Pat Symonds, chief technical officer of Formula 1.
    I will look forward to that of course, but I guarantee we won't be looking at anything remotely like the two strokes we have firmly implanted in our brains!
    Strokers Galore!

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