power piston material

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power piston material

Postby patryk » Wed Dec 23, 2009 8:07 am

I read that PTFE has a lower friction than graphit, why everyone use
a graphit instead of PTFE for power piston?

Patrick, Poland
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power piston material

Postby stan.hornbaker » Wed Dec 23, 2009 12:28 pm

PTFE vs. graphite:

PTFE is difficult (almost impossible) to machine to the fit in a given cylinder compared to graphite and will not withstand the higher temperatures that graphite will.

The fit of the piston in the power cylinder should be such at to slide freely through the open cylinder and take 10 to 15 seconds to slide through a clyinder closed at one end.

Graphite & Pyrex cylinder pairs can be bought from
Look for the link n the "Luffin" description, "graphite piston & Pyrex cylinder".
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