Piston/Cylinder O Ring Fit for a Smooth Running Model Steam Engine.

Free engine plans at myfordboy.blogspot.com
I belive the secret for a smooth runner is a good piston to cylinder O ring fit.
If the fit is too tight the engine may run perfectly well on compressed air but not on steam. Here I show my method. The piston is slightly undersize and does not touch the cylinder walls.

[@johnwynne-qx6br]

Nice to see the axminster micro lathe used for the job. Great video and very useful.

[@RetroSteamTech]

Brilliant 👍👍 I really liked using a drill bit to get the size for the O-ring groove, must remember that. Cheers, Alan.

[@nobbysworkshop]

Thanks for sharing. I'll try silicon O-rings on my next engine. I haven't got to the cylinder and piston yet. Cheers Nobby

[@GermanDarioCarte]

Cómo siempre, excelente trabajo. Saludos desde san Luis, argentina

[@UCanAlso]

Excellent, I made a similar one, 😁

[@Smallathe]

NICE! :)

[@jae878]

Very cool! Is there a ratio of the bore size to stroke length that works best? Or does that ratio change as the size of the engine increases? Thank you for sharing. Always enjoy watching.

[@myfordboy]

I don't think so. The ports on the block need to be spaced apart enough to be covered as the cylinder oscillates and this could not be achived if the stroke were too short.

[@garymucher4082]

Interesting. How long will that "O" ring last before it needs replaced?

[@myfordboy]

A long time.

[@ianpendlebury9503]

What material is the O-ring made from? It doesn't look like the usual buna 'rubber'.

[@myfordboy]

Silicon.