Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Please do not think I'm being critical in a casual manor, but since you are asking for input, I will give a critic of what I see.

That boiler looks to me to be just a little bit undersize for a Stuart #9, as it appears that the cylinder is a significant fraction of the boiler's diameter, and that boiler isn't any too much longer than the cylinder either. That #9 is going to eat through one heck of a lot of steam with each stroke even if not under any load!

It appears that the inside of the cylinder is showing rather heavy machining marks from being bored, and I would think that a careful honing job would be very beneficial there.

Need I mention that all of that uninsulated steam line is a real efficiency killer, while at the same time having a governor in line might be cause of a further restriction unless really properly built and adjusted (ie: fully open) at zero throw-out?!?!

Possibly the exhaust is overly restricted using smallish piping from the cylinder's exhaust, through the oil separator and into the condenser/water tank and onto the exhaust vent from there.

I cannot judge the efficiency of the fire heating the boiler, but to get all you can out of that unit, it will need the most efficient heating you can manage.

Engine has no issue running, I got the entire engine smooth as butter and can rotate on just 5 psi, however within about 2 or 3 minutes,  75 PSI is completed depleted depending on how fast I run the engine.  Even on a low idle, the steam depletes.    The governor remains fully open unless I run it at balls out.       

If you know of a better burner option for these HB's let me know. I know keith appleton uses blowtorch nozzles.  I feel if I got the heat source better, it might be able to run it.