I have just bought Windrush a 1972 Morris 1000 pick up converted to steam.

At present the piston rings are made of carbon and they are stuck in the groves. The cylinders are Stainless so I am limited with what I use for rings.

I am going to use Phosphor Bronze but as I am new to steam I wondered if any one had used it with stainless because I am told I would be breaking new ground something I am not keen on doing without.

The O/S diameter of the pistons are 2 inches 1.4 inside with 4 X 1.25 grooves and 1 X ¼ groove in case there are ready made rings on the market.

According to the build articles in Model Engineer the pistons are assemblies. If you dismantle the pistons can the rings be freed up?
Cheers
Mark

Freeing them off isn’t a problem and I do have some spares to replace the broken one but the existing carbon rings are so worn I don’t think they are the right material and thought bronze would be a better material.

The other alternative would be to change the liners for cast and have cast rings.

I believe it would be a retrograde move to change the material. What you have is good for high temperature, high pressure, low friction. Essentially very similar to the carbon based packing glands used in extreme environments when brass / bronze give up.

It's used in the aerospace industry. Seems you have spare material, but I can provide you with supplier details if you run out.

If you do change, please think carefully about your lubrication strategy.

Readily lends itself to laser / water jet cutting.

Best wishes
Greg

by the way - congratulations on getting Windrush. I think you've got a great car (pick-up!).



Edited 1 times. Last edit at 11/28/08 06:03AM by Greg Walker.