Single Cylinder Opposed

[extropic]

I continue to be amazed at the rate of your build.

I'm wondering if the spark plug and valves have 3 independent ports or are to be implemented via a single tapped hole.

IIUC, you intend to use O-rings as piston rings. You might want to consider using X profile rings to better resist "rolling" an O-ring.

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[rdean]

Each has it's own port.

I have never had a problem with the o-rings on my other engines. I am trying to imagine how the o-ring would roll if properly installed.
Thanks for the comment.
Ray

 

[rdean]

I cut out the two outer connecting rods and installed the bearings in the ends.


Cutting relief slots in the end of the arms for the rod cap bolts.


This is how I drilled the holes for the rod bolts.
It may look a little dodgy but the holes came out straight and true.


Thanks for looking
Ray

 

[Eddyde]

Man, you're flying through this build! What's it been 2 weeks? Similar projects seem to go on for months or even years. Everything looks top notch too...

 

[rdean]

Yes this part of the build is going very well but there is a lot left to figure out before it will run.
I have waited my whole life to have the time and money to be able to build things in my shop so I am enjoying it.
Thank you Eddy for the kind words.

Ray

 

[rdean]

I sawed through the center of the rod bearings, enlarged the holes in the caps for 4-40 cap screws, threaded the rod ends, reassembled and drilled the rod bearings to size. Then I gave them a little shine.


Here they are installed on the engine. I did have some minor fitting to do on the rods but now they move smoothly. I don't have the o-rings installed yet so things might change but for now all is good and smooth.


Thanks for looking
Ray

 

[rwm]

What a crazy cool looking engine! Two rods for one piston.

 

[rdean]

One cylinder
Three rods
Two pistons.

It is crazy looking.

Ray

 

[Firstram]

I really like the height!
Any concerns about the 4-40 rod bolts pulling out since the uppers are in tension? With 2 conn rods it’s half the force but, still.

 

[rdean]

That is something I hadn't thought of and could happen I suppose. I don't think it will be likely to happen on this project as the compression ratio is fairly low but something to keep in mind. Thanks Firstram

I think two 4" flywheels will be best for this model.
I could make up several reasons for the smaller size but really I have the material for the 4" wheels so 4" it will be.



Aluminum inside.


Pressed together, cleaned up, with split tapered retainers.


Next will be to give the flywheels a good coat of paint and the retainers a little shine.

Thanks for looking
Ray