Got a Stuart vertical engine, model 10v, piped up to a PM Research
boiler. The engine runs great 5lbs of air but will not run on steam.
Good dry steam comes out the exhaust but will not run.
Opened up the steam chest and nothing blocking the ports.
Any ideas, suggestions or tips?

Thanks
Jim

Got a Stuart vertical engine, model 10v, piped up to a PM Research
boiler. The engine runs great 5lbs of air but will not run on steam.

Tell us some more. How does the engine turn when you turn it over
by hand? My only guess is that the heat is making something expand
and therefore it cannot turn.
Do you have a pressure gauge on the boiler? What pressure are you
applying?

chuck

Being a single cylinder engine its not self starting, have you turned it
over on steam to try and kick it off. I built a 10V and liked it, it ran
well on air but I never had to opportunity to try it under steam.

wrote:

Got a Stuart vertical engine, model 10v, piped up to a PM Research
boiler. The engine runs great 5lbs of air but will not run on steam.
Good dry steam comes out the exhaust but will not run.
Opened up the steam chest and nothing blocking the ports.
Any ideas, suggestions or tips?

Thanks
Jim

Chuck Sherwood wrote:
Got a Stuart vertical engine, model 10v, piped up to a PM Research
boiler. The engine runs great 5lbs of air but will not run on steam.

Tell us some more. How does the engine turn when you turn it over
by hand? My only guess is that the heat is making something expand
and therefore it cannot turn.
Do you have a pressure gauge on the boiler? What pressure are you
applying?

chuck

When turned over by hand it has some compression which it retains when
I flip it over while opening the throttle.
Not sure about the pressure, no gauge, but same set up will run my
Stuart number 9 mill engine no problem.

Thanks
Jim

When turned over by hand it has some compression which it retains when
I flip it over while opening the throttle.

It has compression when turning it over in the same direction that
the steam should be forcing it to turn???? Sounds like the valve timing
is off.

Chuck Sherwood wrote:
When turned over by hand it has some compression which it retains when
I flip it over while opening the throttle.


It has compression when turning it over in the same direction that
the steam should be forcing it to turn???? Sounds like the valve timing
is off.

But it runs fine on air.
Maybe the steam is cooling down before it can do work?

How about your steam connection to the engine, is the steam pressure
getting to the engine?

Rex B wrote:

Chuck Sherwood wrote:

When turned over by hand it has some compression which it retains when
I flip it over while opening the throttle.



It has compression when turning it over in the same direction that
the steam should be forcing it to turn???? Sounds like the valve timing
is off.


But it runs fine on air.
Maybe the steam is cooling down before it can do work?

Chuck Sherwood wrote:
Sounds like the valve timing is off.

I have read info on various Steam sites that indicates valve timing
should be 10 degrees Earlier on Steam engines compared to Air powered
ones....... I would think it would run either way, but give a look
anyhow. Something doesn't make sense.......

Grummy

wrote (clip) Something doesn't make sense.......
^^^^^^^^^^^^^^^^^
What bothers me is that all the obvious answers we have been offering ought
to be obvious to the OP. When you open the steam valve to the engine, and
it doesn't turn, you turn it by hand. Is there any indication that steam is
entering the cylinder and coming out the other end? Does the cylinder get
warm? Does it drip water? It seems like it HAS to be a blockage somewhere
in the supply. Can you crack a connection and have it hiss at you?

No matter how you turned the flywheel steam was constantly shooting out
the exhaust. Nice dry steam.
So I re-opened the steam chest back up and found some grit/goop in with
the slide valve. Just a tiny bit but after reassembly the engine kick
off and ran great. Guess maybe the goop was keeping the valve from
sealing tight and I just missed it the first time it was opened.
Not sure why it would run on air though. Just glad to get the engine
running on steam.
Thanks for everybodies' suggestions and help.

Jim