Atkinson engine

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Gordon

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Great work. At least you have proven that it can run.
 

propclock

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Fantastic you are a true owner of a Unicorn as far as I have read, like the guy that routinely actually uses his Quorn to sharpen an end mill.
Congratulations ! what is all the liquid in the center? I think as an outside observer
the CDI ignition helps as mentioned by Grim in another Atkinson post and a large flywheel.
The proof is in the running, again congratulations.
 

dsage

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Wow. Fantastic. And it runs with such authority too !!
Looks like you have wonderful compression. What process do you follow to make your rings. Many have been discussed on HMEM.
I think I might abandon my Gingery version (that I considerably modified) and start over.
So, to be clear, you didn't change anything from the original drawings presented on HMEM earlier. I don't want to go down a dead end again.
Thanks much.
A couple of words would be appreciated.
 

dsage

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Fantastic you are a true owner of a Unicorn as far as I have read, like the guy that routinely actually uses his Quorn to sharpen an end mill.
Congratulations ! what is all the liquid in the center? I think as an outside observer
the CDI ignition helps as mentioned by Grim in another Atkinson post and a large flywheel.
The proof is in the running, again congratulations.
Propcock the water is for cooling. There is a passage from the hopper to surround the cylinder. The Gingery uses this method as well.
 

gg89220

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I bought the segments, it doesn't have too much compression I threaded the valve stems easier to find the right spring flexibility the ignition point is precise
 

stragenmitsuko

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A fine runner

Félicitations !

You dindn't use the governor as gar as I can see ?
 

dsage

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I bought the segments, it doesn't have too much compression I threaded the valve stems easier to find the right spring flexibility the ignition point is precise
Segments??
I assume you mean the rings? Good idea.
Excellent idea for adjusting the springs.
Thanks
 

dsage

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Outstanding! Congratulations!
They DO run!

John
They??
Well. I had little doubt (if made properly) the Pendegrast designed engine would run. It's the Gingery version that has problems.
 

Steamchick

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gg. I think you have made an excellent model of this engine and justly deserve the Model of the Month for this one. A true bit of craftsmanship to make such a sweet running engine, of a relatively difficult design. (Looks easy, but so many comments about difficulty of making them run suggests you have "the knack").
K2
 

dsage

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gg. Would you be so kind as to check the positions of your pistons when they are fully to the left in the cylinder with respect to the spark plug hole. I have redrawn the drawings and run an animation and this is what I get. The spark plug hole seems to be partially block by the piston. I'm just trying to confirm this is correct.
Thanks

1616415043073.jpeg
 

dsage

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Excellent. Thank you very much. I'll consider it normal and continue. That's good. I don't have to go looking for errors in my re-draw.
Thanks Again.
 

dsage

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Yes. A book to be avoided at all costs. See various other threads on the Atkinson engine.
 

dsage

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If you've been following along the plans are already posted back in message #5 and elsewhere in another thread. I'm just re-drawing those plans to be sure I understand them.
 
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