lubrication free materials

[john7appleyard]

I am designing a twin cycinder engine which will have very poor
access opportunities. Can you recommend materials for a lightweight
displacer and a power piston which will not need lubriation.

Thanks.

[iron_goober]

Well, if you are making a small model engine, and you don't have a lathe, using JB weld to make a piston in a brass cylinder works quite nicely. Read my other post in the Educational engines forum. Are you making an LTD engine or one that runs hotter? Because for LTD's, styrofoam works great for the displacer.

[john7appleyard]

I saw the answer in another of your posts john; Brass and ally. I am going to get it lathed, It is a prototype for evaluating a novel energy source. I don't want to worry about maintainence or build in a lubricant reservior.

Now I've got to go in search of metal expansion or it will pinch!

[iron_goober]

Graphite is of course the best answer for something that doesn't need lubrication, but and aluminum piston riding in a brass, bronze or steel cylinder works well also.