The Oil Field Engine Society

By Staff
1 / 2
Goodwin 20 HP Reid.
2 / 2
Darke County Steam Threshers.

1231 Banta’s Creek Road Eaton, Ohio 45320 email:

The thing that I think I enjoy the most about the Old Iron hobby
is the great fellowship we have with the many great folks that like
old engines. In my opinion, they are some of the best people I have
ever known. I hope that the experience that you have had is the
same. This month we have an article written for the News by Mr.
Charles Gray, 9620 Ravenna Road, Chardon, Ohio 44024 Mr. Gray shares with us his experiences setting
up oilfield engines. He didn’t send any photos, so I’ll
throw some in the pot this month. The first is a 20 HP Reid owned
and restored by Leroy & Nancy Goodwin of Leipsic, Ohio. The
next is a scene from the oilfield engine area at the Darke County
Steam Threshers show last July.

Lastly, as always, if you have anything you would like to share
in the News let me know. Also for free membership in the OFES, call
or send an S.A.S.E. Please visit the oilfield engine society
website at

Yours Fraternally, Russell Farmer.

Setting Up Your Oil Field Engine

Acquiring an oil field engine can be an exciting event in our
lives, regardless of whether it’s the first or the fourth.
There is a certain beauty in that old engine that takes a special
person to appreciate. Those of us who collect engines can see
beyond the rust and grease to behold what is certainly one of
mankind’s greatest inventions. The ‘bark’ that an oil
field engine makes while running is music to our ears; but only
‘so much noise’ to the uninformed. However, that beauty can
become a beast when you are trying to get it to run for the first

This article will offer some advice regarding your oil field
engine and is directed more towards the less experienced person. It
will offer tips and techniques that have been found to be
successful. Keep in mind that there are also many other methods of
successful operation, and it is hoped that this article will
encourage others to write about their experiences.

There are some basic precautions that are worth repeating. It
goes without saying that the engine has to be on a substantial
base. You should know how to shut it down in an emergency. Keep a
fire extinguisher handy. If you are using a hot tube for ignition,
never look down the chimney to check the hot tube while the engine
is running. They have been known to burst, and they can blind you.
Use a mirror on a stick for this purpose. Keep the kids back. And
please, don’t feed your fingers to the engines.

Don’t ever speed them. When they were new the self-destruct
speed of an average 20 HP flywheel was around a thousand rpm. The
old engines may have cracks in the flywheels, which will lower the
critical speed. The cracks could be the result of a single impact
or mishandling event. Or, they could be fatigue cracks which result
from repeated applications of ordinary loads. Fatigue cracks can
occur anywhere on the part. They always start at a stress
concentration, which could be a surface defect, an inclusion or
void in the casting below the surface, or at a change in section,
such as where the spoke meets the rim. All machines, after some
period of use, will develop fatigue cracks: from 747’s to
pencil sharpeners. These cracks may not be visible to the eye and
only be detectable by using sophisticated equipment. The cracks
will progress slowly under light loads and rapidly under high
loads. When a crack propagates to the point where the remaining
metal can no longer carry the load, the piece will break. The
highest loads in a flywheel are at the rim. They are the result of
centrifugal forces caused by rotational speed. The centrifugal
forces will be the same, whether the engine is loaded or not. The
centrifugal forces on a rotating part increase by the
‘square’ of the speed. In plain talk, this means that if
you double the speed, the forces increase by four times. Triple the
speed and the forces increase by nine times. Quadruple the speed
and the forces will increase by sixteen times. At a critical speed
the flywheels will disintegrate with possible lethal results for
those nearby. Keep the speed below a hundred and fifty rpm. If
someone is demonstrating how fast his engine will run, it’s
best to walk away.

Many oil field engines used natural gas directly from the well
site as a fuel. Yours will probably be running off of propane,
which has a higher energy (btu) content. Some owners will install
an accumulator tank of approximately two gallons capacity in the
gas line to the engine. If you are running only with spark
ignition, you won’t need an accumulator tank. The purpose of
the accumulator tank is to provide a reservoir of fuel, so that
when the engine takes on a volume of fuel, it won’t starve the
supply to the hot tube causing the fire to go out. One way to avoid
the requirement for an accumulator tank is to use two propane
tanks; one for the hot tube and one for the engine. An added
benefit of this method is that when the engine supply tank becomes
so low that it can no longer fuel the engine, it can be switched to
the hot tube, where it may serve for several more hours. Locate the
engine supply tank away from the engine, so that you can shut off
the fuel if an emergency arises where you cannot approach the

Install a gate valve on the air inlet pipe to the engine. For an
initial setting on engines in the twenty horsepower range, close
the valve down to about a one-eighth inch opening. If you can find
a gas control valve with a ‘diamond shape’ opening, use it
to control the fuel supply. Before installing the diamond shape
valve, put a mark on the handle where it just closes. Move the
handle to the point where the valve just opens, and this will be
the initial setting for this valve. Most of the original gas valves
supplied with the oil field engine had rectangular openings which
makes it difficult, if not impossible, to regulate the small amount
of propane fuel necessary to run the engine under no load. You can
still use an original gas valve for the sake of appearance, but you
will have to also install a needle valve in the fuel line. The
needle valve will allow the precise control of the fuel. The needle
valve will probably have a three-eighths or one-half inch pipe
thread as compared to a one inch pipe thread on the original gas
valve, so you will have to be innovative with your plumbing.

You can still use your belt driven governor if you have one. If
the governor is of the type typically seen on Bessemers, plumb the
gas right through the governor; the needle valve will still control
the fuel. On other types of belt driven governors, a Reid for
example, you might want to disconnect the linkage.

There are oil field engines in the hands of collectors that do
run ‘off the governor’ without the need for a needle valve.
They deserve much credit because they are in the minority. If you
have an engine without much governor wear and you have the
necessary skills, then set it up to run off the governor and
prepare to receive many compliments. Again, there are words of
caution. Some of the belt driven governors had an idler pulley
arrangement that would shut off the fuel in the event of a belt
failure. Without this feature, if the belt broke, the engine would
go to full throttle and, under no-load conditions, reach a critical
speed in seconds. Or, a malfunctioning governor, itself, could
allow the engine to suddenly over-speed.

If you have an extra threaded port to the cylinder, install a
large petcock to make it easier to purge a ‘flooded’
engine. These engines seem to flood very easily. If you have to
remove the spark plug to purge a flooded engine, there is a word of
caution. You can destroy the coils in a Wico magneto if you
‘trip’ it while not providing a path to ground for the
resulting electrical current. If there is no external path, the
voltage will find an internal path to the ground through the
windings on the coils. When enough coils become shorted out, the
magneto will no longer provide an adequate spark. Remember that
just because you see a spark in an external spark plug test, it
does not guarantee that the spark will jump the gap when the plug
is in the engine and under compression. If you have to remove the
spark plug to turn the flywheels, lay the plug on the engine with
the wire still connected, and provide a ground path from the plug
to an unpainted place on the engine.

The hot-tube chimney (formerly known as a furnace) originally
had an asbestos liner, which is usually gone. Some engines will run
without the liner. If you have access to some asbestos stock, you
are fortunate. Line your chimney and don’t worry about asbestos
poisoning. The asbestos laws were written to protect those who were
working with asbestos day after day for many years. Using
reasonable precaution, fifteen minutes of exposure will not be
fatal. Without the asbestos liner, you might have to cut the bottom
out of a tin can and set it over the hot tube chimney on windy or
cold days in order to retain the heat. Fire up the hot tube and
wait about ten minutes. If you are using only one propane tank,
make sure that the valve in the engine supply line remains closed
during the warm-up period, otherwise gas may leak past the
engine’s intake valve allowing the engine to flood. The two
tank method will allow you to keep the engine supply gas shut off
at the tank until you are ready to run; with the added advantage
that you won’t have to disturb any previously determined gas
valve settings. Some engines will require a very precise setting of
the gas valve, which can be difficult to find again. When the hot
tube has an orange glow, you are ready to run.

Turn on the gas supply. Open the needle valve, if used, about
one turn. The gate valve at the air inlet and the diamond shaped
valve, if used, will be set as previously described. Rock the
flywheels three or four times backwards against compression and the
engine should start. If it doesn’t shut off the gas to the
engine, open the petcock and rotate the flywheels three or four
times to purge any gas. Close the petcock, open the needle valve
one eighth turn more (or open the diamond valve a very small
increment more), turn on the gas and rock the flywheels as before.
Don’t bother with the gate valve. Repeat these steps until the
engine starts. As it warms up, some minor adjustments to the gate
valve and gas valve may be necessary. You may end up with one gas
setting for starting, and another, slightly leaner, for

Some operators prefer to put their foot on a flywheel spoke
while rotating it backwards for a little extra push. This is risky,
but with a magneto ignition, at least you will know from the
position of the flywheels when the engine will fire; so you can
remove your foot from the spoke before the engine fires. With a hot
tube ignition, this point isn’t so well defined and is
variable, so it’s better to avoid the ‘foot in spoke’
procedure. It is possible to be ‘launched’ with deadly
results if you should come down on a running engine.

Some choose to start their oil field engines by belting them to
a tractor or another engine. This procedure is often seen at shows,
and is certainly a crowd pleaser. If you use the belting method
while trying to start your engine for the first time, the engine
will probably be turning faster than it should or would, so any
fuel and air setting that you arrive at might be incorrect and you
may not find the settings that allow an easy hand start.

This belting procedure can also be dangerous. If you have access
to the October 1989 issue of GEM, check out page 21. Briefly, here
is what happened. An experienced collector had belted his 20 HP hot
tube Muncie engine to a John Deere ‘W’ power unit for
starting purposes. The engine started, but the eight inch wide belt
slipped off the power unit and wrapped itself around the sixty inch
flywheels of the Muncie. No one could get close enough to the
engine to shut it down. The free end of the belt tore off the roof,
knocked the screen cooling tower over and luckily, ripped the fuel
line from the engine, causing it to stop. Here is a direct quote
from the article: ‘Can you imagine what could have happened if
I had all my engine friends over to see the Muncie engine run?’
Be careful out there.

The following paragraph has been taken from an operator’s
manual for the Bessemer gas engine and contains some helpful
information pertaining to hot tubes.

‘Hot tube igniters are made from either nickel alloy or
wrought iron, having an inside diameter from
5/16 inch to 3/8 inch,
and a length usually within the limits of 6 to 8 inches. In extreme
cases, however, the limits may run from 3 inches to 10 inches. A
long tube causes an earlier ignition than a short tube, when the
inside diameters are the same, or a larger inside diameter tube
causes an earlier ignition than a smaller inside diameter tube of
the same length, so it may require some experimentation to
determine the length of the tube that will give the best

The manual goes on to say that the nickel alloy tube is ‘far
superior’ to the wrought iron tube unless the gas has a high
sulfur content. Collectors have made hot tubes from stainless steel
pipe or stainless steel solid rod using alloys 316, 304, or 303.
Hot tubes made of ordinary steel pipe will not last very long.

You also have to consider the type of finish that you want on
your ‘new’ old engine. Some collectors want an appearance
similar to that of a brand new automobile right off the showroom
floor. This is okay, but most never looked that way, even when new.
But some did; they were called ‘carnival’ engines. They
were painted with bright colors and had lots of striping and chrome
plating. As the name implies, they were sold to the carnivals and
traveling circuses, where they had to fit into the total scheme of
things. The condition of your engine will dictate the minimum
amount of finishing that is required. Sometimes, refinishing will
actually cause an engine to decrease in value. Before you start to
wire brush or sandblast, look it over very carefully and give
plenty of consideration to your options. An engine that is a dull
black color with no paint whatsoever, but is clean and well oiled,
certainly has a lot of charm. It will look very old and will not
look neglected. But sometimes it’s better that your engine be
painted for whatever reason. That’s what’s nice about
collecting engines! There are no rules!

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