What are the symptoms Eric? Don't forget that steam will rapidly turn to water in the pipes which you have to pump through before it will run. Also, on steam it gets a lot hotter, different metals expand by different amounts and you will need to adjust the springs. Finally, the pistons maybe expanding in the cylinders and jamming.

Neil

Hi Eric ,

The steam entering your cylinders is not actually much better than kettle steam and whatever the boiler pressure the pressure in the cylinders will be much less running on no load . This means that the steam is very wet and there is a large amount of water going – maybe 30 % of the total steam flow is water and even more after some condensation .

This very wet steam is very different in its properties to air . In particular the water part of the wet steam can condense out into actual slugs of water (its mist otherwise) .

One of the most common causes of engines running on air but not steam is hydraulic lock . Its very easy for one of these slugs of water to get trapped between piston and cylinder head and being nearly incompressible it stops the engine . Usually actually caused by ports being out of place either by design or as made .

Two possible conditions for ports being out of place :

(1) Too big a dead zone between inlet and exhaust ports – neither is open .

(2) Port in cylinder too far away from cylinder head leaving a trap .

Thermal expansion of piston in cylinder has a near zero probability of being the cause of problems .

Regards ,

Michael Williams .

Right on Eric, not much bigger than a coffee cup. Looks like it ought to have a much bigger flywheel. Have you tried a bit of blow lamp on the steam pipes?

Robin

Hi EM

So you work in a Dunny, mate Kerrriste. I remember 40C after 25 years in the middle east, Now 55C is real mustard (in a desert camp near Riyadh). Frying steaks on the bonnet of your Landcruiser. 3 hours exposure and you are history. Happy days

Seasons Turnings

Robin