Page 1 of 1

Machining pyrex cylinders? Graphite for pistons?

Posted: Fri Oct 26, 2007 12:00 pm
by iron_goober
I constantly see so many engines with graphite pistons and pyrex
cylinders, but I don't know how people machine out the pyrex. I know
just using regular tooling doesn't work. Can anyone help me out on this?

I was reading Jim Senft's book "Ringbom Stirling Engines" again and I
had forgotten about the concept of an Alpha type ringbom engine.
Reading it has inspired me to try and build one. However, I'd like to
build it out of pyrex so I can actually see what is going on inside
the engine so I can make adjustments. Any help you all could give me
would be very much appreciated.

Oh, by the way, where is a good place to get piston quality graphite,
(I've only used aluminum, brass and JB weld) I know Senft says that
EDM quality is the best...but dang, it is expensive!

Thanks again.

Machining pyrex cylinders? Graphite for pistons?

Posted: Sat Oct 27, 2007 10:10 am
by stan.hornbaker
You do NOT Machine Pyrex for cylinders.

Visit or call them at numbers listed for a free sample air pot or a pyrex-cylinder/graphite-piston matched pair.

has piston/cylinders at $13.95/pair ppd. Contact them for special pricing on three or 4 pair shipped together.

See the previous topic, "LTD Displacer Cylinder Plastic Material Source" re displacer cylinder.