I have been having a fit installing packing on the rear heads of our 30 HP Stanley engine while it is still in the Mt. Wagon. The packing has been wadding up, piling up and in general, not being user friendly. A mechanic friend suggested using high temperature O rings. I Googled High temperature O rings and I came up with using O rings made by either Chemraz or Kalrez. The Chemraz 615 is designed to be used from -10 degrees F and up to 615 Degrees F. The Kalrez 4079 covers the same temperatures. Both can handle occasional spikes in temperatures over 615 degrees. With a good assembling lubrication, the O rings would stay put when the heads are tightened. Has anyone tried using these? Any thoughts?

I received an email saying that David Nergaard has used the O rings successfully. I finally succeeded in getting everything sealed up tight on the 30 HP engine.

Worked fine on my Model H - never had any leakage.
Mike

I got the heads to hold tight with 1/8" McMaster-Carr stuffing box packing. It took the precision of a surgeon to drive the packing back in under the last threads of the heads and then to form the packing to accept the block as the heads were screwed down. I am sure that O rings would have worked better. I have a new cylinder and steam chest cover. I had to chuck the steam chest cover in my lathe and cut just a little relief under the threads for the packing to hide and to stay put. Worked great and the packing stayed put this time. O rings sounds like the way to go though.