Build Your Own Steam Engine – Part 1

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The approximate one-hundred-year life of the steam engine is what this article is principally all about.

A brief history of steam power

Before the Civil War the steam engine was in its infancy, and immediately after the war the use of steam increased and made mechanical history, until the beginning of World War One. While the steam engine industry enjoyed a rapid and prosperous business, the ideas of the internal combustion engine, and even electricity, began to catch on and by the time the world war was over, steam had about been displaced with the more modern power plants. Thus the era of the steam engine was past history, generally speaking.

As the old-time steam engine builders considered their drawings only temporary and, their purpose had been served, incontinently destroyed them. With information on old steam engines scarce, that is compiled and contained herein, will, it is hoped, prove as interesting to the layman, as to the enthusiast. Any and all statements, or apparent quotes, of any other person, living or dead is purely co-incidental, and is caused only by different educational training methods.

In composing this article, I have drawn greatly on the conversations with a great many of the old-time steam engine men, such as: old-time locomotive engineers, old-time steam traction engine men, cotton gin and saw mill operators, and in fact, any person who ever had any part in the operation of a steam engine or boiler of any sort. And to these men, when as a boy, I used to look up to, with admiration and respect, because they were my friends, I respectfully acknowledge, with gratitude.

My love for steam engines began about 60 years ago, when as a boy I living on the homestead of my grandfather, who had settled on Revilee Creek just after the end of the Civil War. Soon after getting out for farming and livestock raising, he bought some cotton gin machinery which was operated by a steam engine and boiler. Later on he added a sawmill and gristmill.

Accident on cotton gin machinery

This machinery was all operated several years before I can remember, but I do remember seeing the old location, with all the excavations, various rigid foundations and remains of this old-time operation. I also remember seeing photographs and hearing conversations of the “Old Timers” telling about the operations and events that happened during the 20 or 30 years of its operation.

They told me of an accident that happened during its life of operation, about a man who was operating the gin stands. This man was making some adjustment on the gin stand saws, which were 6 or 8 inches in diameter and numerous, probably 60 or 70 to this particular gin stand; and located on a shaft or mandrel, approximately one-half inch apart, and ran between metal ribs. The teeth of these saws pulled the lint from the seed and the cotton was brushed away by fiber brushes.

Owning to some malfunction of the machinery, this man put his hand into these saws while in operation, consequently, the torque pulled his whole arm into this gang of saws, which sawed his arm completely off. As terrible as this accident was, the man lived over it.

Grandfather’s steam equipment

My father was the older of several brothers, so he naturally had charge of his father’s machinery to a great extent. My father told me a lot of true stories about the steam engine and boiler that operated this machinery.

My grandfather’s first engine and boiler was known as a portable engine, meaning the engine was rigidly located on top of the boiler. This kind of a rig was generally on wheels, or may even be on wooden skids, but, it could be moved around to a certain extent. This engine proved to be too small, so he sold it and bought a larger and more powerful engine and boiler.

His second rig was not a portable outfit, but individual units. The boiler was the horizontal type with return fire flues or tubes. The boiler was suspended 2 or 3 feet above the ground, so as to accommodate the fire grates and ash pit. A masonry furnace was built around the entire length of both sides and rear. This long furnace was very advantageous, to the fact that long lengths of wood, and even the long slabs from the saw logs, would make fuel to fire the boiler. The engine of this setup was a center crank job. I remember, from photographs that I have seen. The engine was located several feet from the boiler, and the power takeoff was by a wide canvas belt on one of the flywheels and then belted to a jackshaft that had pulleys to run the other machinery.

Gasoline and electric power replaced steam on the farm

As I was growing into manhood I was in school most of the time, and by the time I was a man, gasoline and electricity had taken over as the practical power source to run most of the machinery in our region.

When I started out on my own, I never worked any place that was operated by the old-time steam engines, but I always dreamed of the day when I would some day own my own steam engine just for a hobby. On weekends and holidays I would drive out into the neighboring locations to see these portable engines doing their work. At this time, steam locomotives, however, were still used on the railroads in this country. These old steam locomotives used to fascinate me very much.

Car accident leads to steam fever

In 1954, when I was 52 years old, I was in a serious automobile accident and after two years in a hospital, I was pronounced a totally disabled person and physically unfit to do any gainful work. As I had spent most of my working life in precision work, mostly airplane manufacturing, I set out to find a steam engine.

After several weeks and several hundred miles, I finally found a 20 hp center crank steam engine and a 10 hp center crank steam engine. I also found a 20 hp vertical steam boiler to operate these engines with. After cleaning, adjusting, painting and otherwise getting them in good running shape and in good condition for exhibition, I really came down with the fever.

Desire spurs building steam engines at home

Now it began to look like it would be impossible to find any more engines, so I started to think about building my own engines. My experience that I had gained by working in these industrial precision machine shops was going to pay off. I began by buying two or three metal working lathes, a power hack saw, an acetylene welder complete with cutting torch, an electric welder and accessories, and numerous smaller machines and tools.

I went to work building my first steam engine. In a few weeks I had built a small 2-inch bore side crank, piston valve steam engine that ran, ran good and ran good on live steam. After operating this engine for several weeks, day by day, I decided to build more of these engines.

As a result, I have built several different sizes and designs that I have in my machine shop and adjacent buildings. Most of these engines are built from re-constructed and re-machined salvage parts from other machinery which I will tell about later.

Simplified explanation of a double action steam engine

The steam engine, being similar to some other sources of power units, is operated by steam pressure properly metered into a cylinder containing a piston fitted to close tolerances and fastened onto the piston rod running through the front head, containing a counter bored packing nut. This description applies to a double action engine only, which is the more popular type.

In this simple explanation of a steam engine, I am making no attempt to explain any scientific theories, or the practice of even a mechanical engineer. What I am trying to say is that I have built several steam engines that run good on live steam or even compressed air. So, anyone with the mechanical inclination and a few of the basic machines for working with metal can build a steam engine that will run good and that he will be proud to show and operate it for viewers.

The piston valve

Now for a word about the piston valve we use in a part of these engines. This valve is composed of two pistons on a common piston rod spaced far enough apart to allow a steam storage, or steam chest, between them and fitted inside a cylinder with close tolerance. Properly spaced ports in this cylinder allow the steam to move into the drive cylinder with the pistons as they travel in their reciprocating movement.

This reciprocating movement of the valve mechanism can be obtained by a choice of several ways. The older and probably the more satisfactory method is probably with the crank, cam or eccentric, because of the ease of arriving at the length of travel, which, of course, can be obtained by the location from center. This in turn, regulates the length of travel so as to allow them to pass the ports completely.


The valve setting, which is called “timing,” is the starting of any particular cycle in reference to the starting cycle of the main crankshaft. Naturally, it would seem like the valve movement and the movement of the main drive piston should be in perfect synchronism. But, with the steam engine varying with different engines, it is necessary at times to advance or retard the movement of the valves in order to take up loose or sluggish movement. With proper adjustment, this movement neither adds to nor takes away successful operation of the engine.

Timing is generally done by milling cam hub. The hub of the cam in this assembly being put on the crank shaft loosely so that it can be moved forward or backward by means of loosening a set screw, or what ever means it employed to hold it rigidly (which is a must, after perfect timing is established).

The drive piston

Back to the drive piston, which has been secured to the piston rod by means of threads and a lock nut and passing through the front cylinder head, with the counter bored packing nut. It is now joined to the connecting rod through the crosshead by a wrist pin movement and held in perfect horizontal alignment by means of sliding bearings, known as “ways.”

The forward end of the rod is then attached to the crank disc, complete with bearings. By this time the length of travel of the main drive piston is established and the knob on the crank disc must be placed so as to make the throw length the same as the piston travel; meaning of course, the travel of the front side of the piston.

Basic operations and considerations

During the work of building your engine, or maybe we should say components, and assembling them, they will automatically show how a great many of these adjustments must be made and to what tolerance degree must be used. These basic operations will make a simple, but well designed engine that will run.

But, should you stop here, you will have to do a lot of manual operations to keep it going nicely. Automatic control of the speed is very essential. Manual operation is a positive control, but should you leave the engine for a while, a pressure build up could cause severe damage to your engine by letting it run too fast. So, by having an automatic governor for speed control, automatic lubrication and various other automatic accessories, will make your steam engine a great deal more pleasure to operate and after you have operated your engine for some time, you will automatically see how you can improve on them.

During the time you have spent working on your engine you will have seen photographs and no doubt read brief descriptions and specifications of a lot of steam engines. Probably you are one who would like to give your engine the authentic look of a real antique built around the turn of the century.

There are still quite a few of this type and model around. We see a few of them at the old-time steam engine shows around the country. Basically, these old engines are about the same as the ones built later on. It is a fact that ANY steam engine is old now, simply because they have not been built since the beginning of World War One.

Create illusion of age with a flyball governor

As a governor of some design is almost a necessity on a steam engine, the old flyball type is being made now by hobbyists in their home machine shops. This type of governor automatically dates your engine.

The building of a flyball governor gives most of us a sizeable task, but I have seen quite a few that I am sure the maker took quite a bit of pains in making. The flying balls operated by centrifugal force on a vertical shaft surely make a positive valve regulator, and the long belt that operates it is an added feature that draws attention from all viewers.

Consider using salvage machinery

Although you may now have an engine of some degree of completion or want to modify this one or others that you may build, remember, that your engine can successfully be built from salvaged parts of other machinery.

Some times salvage can be acquired just for the removal from the space that it now occupies. The trade and barter method is a good source of procurement. Maybe you have something that you no longer need and want, but some one else might like to have it, so both can profit from such an exchange.

Another good point about the using of a great many parts of salvaged machinery is the fact that most of this machinery is made of good metals and alloys that are stronger and have better machinability than some cast iron ones, and needless to say the cost would be only a fraction. IMA

Continue reading about making your own steam engine with part two: “Build Your Own Steam Engine – Part 2.”

J. Arless Jenkins is from Magazine, Arkansas.