Chain Drive Apposed Piston

[Rdean33422]

I hope you like it.
2" combined stroke
3/4" bore.



Thanks for looking
Ray

 

[johnmcc69]

That's very interesting, similar to the Atkinson.

I would be interested in any more pic's or drawings of what you have made.

That's an unusual engine & a great runner! You did a fantastic job on it!

John

 

[Nerd1000]

A four stroke opposed piston engine is quite the oddball! Very cool, I have thought about how this sort of thing might be done but haven't gone further than that.

 

[Rdean33422]

It was a long road to get to this finish line with several different design changes. I tried using a cog belt but in order to stop the belt from jumping a tooth I had to have the belt quite tight. This caused too much drag on the engine as it would fire but not run on its own. Maybe a different belt with deeper teeth would have helped.
I also tried aluminum gears and as it did run the noise level was way too high. If the gears were inside a housing to muffle the sound it may have been acceptable but it would have been a project in itself.

I will post a few pictures.






I do have more pictures and a couple of drawings if there is a specific area you would like to see let me know.

Thank you all for the kind words and likes.

Ray

 

[minh-thanh]

An interesting engine.
Congratulation !

I will post a few pictures.

Ray

Please...More.

 

[awake]

Wow, great runner! I see the exhaust valve on the top, and atmospheric intake valve at the front ... but where's the spark?

 

[Rdean33422]

The spark plug comes up from the bottom awake.

I don't make many drawings but when there is a possibility of interference I will plot it out.
This is one I did when I reduced the stroke to 1" per piston. I also reduced the piston diameter to 0.75 in hopes I could find a balance between engine power, tooth jumping, and belt tension. I was not successful so went to the chain drive instead. If I had used the chain drive originally I believe I could have stayed with the 3" stroke and a 1" diameter piston.

In order to keep the compression ratio up I had to make the pistons enter the original 1"combustion chamber 0.090 on each. If I remember correctly I am around 5.2 to 1 now.


The gears were cut 16DP so if you need any I have some left over.

Thanks for looking
Ray

 

[Brian Rupnow]

Very nice work. A very unusual and interesting engine.---Brian

 

[Nerd1000]

It was a long road to get to this finish line with several different design changes. I tried using a cog belt but in order to stop the belt from jumping a tooth I had to have the belt quite tight. This caused too much drag on the engine as it would fire but not run on its own. Maybe a different belt with deeper teeth would have helped.
I also tried aluminum gears and as it did run the noise level was way too high. If the gears were inside a housing to muffle the sound it may have been acceptable but it would have been a project in itself.

I will post a few pictures.

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View attachment 143719

I do have more pictures and a couple of drawings if there is a specific area you would like to see let me know.

Thank you all for the kind words and likes.

Ray

I think a gear (or chain!) housing is a perfect job for a 3d printer. Print in PETG or nylon and you can even have an oil bath for all the moving parts.

 

[Rdean33422]

Yes I am sure that would have quieted things down but would have also taken away being able to see the gears turning. Part of the fun is seeing all the bits and pieces flying about do you agree?
Ray

 

[vederstein]

Very Cool!

The chain appears to make quite a racket. Is it very loud in real life?

...Ved.

 

[Rdean33422]

The chain makes a swooshing sound that is not objectionable. The engine is generally louder than a hit miss engine as there is more going on but compareable to my twin with an exposed cam.

Thank you for the question
Ray