Subject: Steam Engine Wanted

From: [email-masked] (Rob Cummings)
Date: Wed, 22 Mar 1995 12:19:42 GMT

Does anyone out there have a small steam engine they would like to sell.
I would like to find about a 5-10 hp engine to tinker with and possibly
run a air compresser, generator, well pump, etc. E-mail to robc@hpbs4550
.boi.hp.com
Thanks a bunch
Rob C

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From: [email-masked] (Barry Workman)
Date: Thu, 23 Mar 1995 06:17:28 GMT

>run a air compresser, generator, well pump, etc. E-mail to robc@hpbs4550

It may be the perspective, but 5-10 hp steam engines IMHO are not small.
I've just finished a small engine, maybe .1 hp on a good day.....
(27.3 cu in but Shearline will lete me enter it anyway)
-- 
    - Barry Workman

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From: [email-masked] (John W.Hall)
Date: Thu, 23 Mar 1995 10:03:29 -0400

>    - Barry Workman 

Yes indeed! They are not for the livingroom! I once owned a "small"
mill engine of about seven hp.The idea was to run a cutoff saw for
stove wood and have fun blowing a whistle. The engine was a full load
for a half ton, size wise, and an overload weightwise, so it must have
been about fifteen hundred pounds and about seven by four feet. The
boiler I had was about three by five verticle and I could only get
enough steam to run at about 20 rpm, as I recall, Nowhere near enough
to do any work. It_was_fun though.:-) I ultimately traded the whole
rig for a lovely little twenty foot boat with a make and break engine.
That too is since gone :-(. I keep dreaming about building a boat
around a three or four horse steam engine, if I could ever find one.
Maybe fifteen years ago there was somebody down south (Florida?) who
offered a set of castings for something like a three horse verticle
but it was pricey.

-	John Hall

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From: [email-masked] (Bart Smaalders)
Date: 24 Mar 1995 17:55:02 GMT

A 5->10 hp steam engine doesn't _have_ to weigh 1000 lbs;
it's just that a lot of the old machinery was designed to 
run for many years.

Perhaps the easiest way of getting such an engine is to get
a hold of an old Wisconsin vertical twin industrial gas engine.
They're about 3.25 x 3.25 bore and stroke, and if you remove
the head & valves and make a simple slide valve head, you can
get a 5->8 hp steam engine (depending on rpm, etc) with minimal
machine work.  Be sure and run a non-detergent oil and change
it frequently.  If you use a poppet-valve head and high-pressure,
superheated steam you can get a lot more power, of course.

My 19' steam launch has an engine converted from a refrigeration
compressor; it is only 2x2.5 (two single acting cylinders) and
puts out 2 hp or so (pushes the boat at 6 mph) when fed with
125 psi, 475 F steam.

- Bart Smaalders

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From: [email-masked] (Mark Kinsler )
Date: Thu, 23 Mar 1995 18:22:34 GMT

>to do any work. It_was_fun though.:-) I ultimately traded the whole

This is an exceptionally interesting discussion for those interested in
the history of technology.  So "small: steam engines are big, and they need
a big, hot boiler to work.  An earlier post and its replies about the
dangers of home-made boilers were equally illuminating.  No wonder the
electric motor and internal combustion engine replaced steam for smaller
applications so quickly.  I suppose that we have to repeat the past in
order to understand it. 
                                                     M Kinsler

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From: [email-masked] (Bart Smaalders)
Date: 24 Mar 1995 18:25:53 GMT

>applications so quickly.  I suppose that we have to repeat the past in

This is a bit of a sweeping generalization.  Remember that if one
produces a steam engine and boiler _with_ _the_ _same_ _level_ _of_
_technical_ _sophistication_ as an internal combustion engine, you
end up with a much more comparable device.  Remember, the
early gas engines had similar power to weight ratios to steam engines.

By way of example, the steam engine in my boat uses technology & stress
levels from about 1880.  This implies 125 psi steam, not too much 
superheat, and a small water tube boiler.  The entire power plant
weighs over 400 lbs, and produces 2 hp.  Not much to compare with a 
Briggs and Stratton, although a lot more pleasant to sit next to
all day.

A friend of mine has chosen to build something else - he has a steam
outboard.  It uses a small flash boiler built from 1/8" pipe, burns
solid fuel and the entire things weighs just under 100 lbs.  It uses
poppet valves, turns 3000 rpm rather than the 500 or so mine does, and
pushes his metal jon boat faster than a 7 hp gas outboard.  The steam 
conditions at full power are something like 800 psi and 800 F, so stainless
valves, etc, are the order of the day.  

Now, keeping this thing stoked (the boiler is about 6" by 12" by 12") 
with pine cones, sticks, etc, is a busy task at full throttle, but it
will troll all day on a bag of wood scraps and smells a lot nicer than
a gas outboard while doing so.... 

Gas engines probably replaced steam engines so quickly because it was
possible to build them cheaply in small sizes and make them portable
for use around the farm, and they could get enough power out to make
planning boats possible.  The fact that you didn't need a licensed
steam engineer to run 'em didn't hurt either, and in those days
gasoline was a waste product from the production of kerosene for
cooking & lighting.  The gas engines were much more efficient than
the steam plants of the day, and the efficiency was "built-in";
in a steam plant the fuel efficiency depends a lot on insulation
and other installation details.

As to the dangers of home-made boilers, in small sizes this is greatly
over-rated.  Using reasonable engineering standards and water-tube 
construction, a reasonably skilled welder can produce a fine
boiler w/o undue risk to himself or by-standers.  The steamboaters
and live steam loco folks are good examples of this.

- Bart Smaalders