The Superior Engine

25 HP Superior engine

Harold R. Keller, Rt. 1, Glouster, Ohio 45732 writes about this 25 HP Superior engine and its manufacturer's history in this issue. Photos by Ruth A. Van Schoor.

Ruth Van Schoor?

Content Tools

Rt. l Glouster, Ohio 45732

Around 1889, Irish immigrant Patrick Shouvlin started a machine shop in Springfield, Ohio. He had a good head for mechanics and put his knowledge to work repairing oil field equipment. With the increased uses for oil, and its discovery in the area, his business flourished. In the 1890s his shop adopted the name Superior. The demand for Superior engines and related equipment made it obvious that a better marketing plan was necessary. Arrangements were made with a fledgling business named the National Supply Company to be distributors of Superior engines, and probably related equipment.

By 1914, Superior was building engines from 2 HP to 100 HP, both stationary and portable, as mine was.

Although building mostly gas engines at this time, Superior was well aware of the advantages of diesel power. Invented by Rudolf Diesel several years earlier, Superior was well aware of the advantages of diesel power. Invented by Rudolf Diesel several years earlier, Motoren Fabric Deutz, among others, were instrumental in its early development. among others, were instrumental in its early development. By 1930, Superior was building diesel engines for oil field use, of a truly superior design.

The engine on the front cover came home to southeastern Ohio in 1934, brand new from the factory in Springfield. Many years ago, I knew a man who hauled it home. At the time, I did not have the foresight to ask him how he hauled the engine home. The engine proper, mounted on the original iron wheels, weighs close to 9,000 pounds. The clutch assembly is a strongly built and heavy piece, weighing about 1,200 pounds. The reversing mechanism and outer bearing are also strong and heavy, so the total weight of this engine is close to 11,000 or 12,000 pounds. It seems likely that back in 1934, it took two trucks to haul it home. The trip alone was probably an interesting experience.

This engine replaced a steam engine, powering an oil field drilling rig. I imagine this new engine made the owners feel pretty sassy, no longer having to fire a boiler for power.

The engine is a two-cycle, gasoline starting diesel, having a 10' bore, and a 12' stroke. This size figures to 1124 cubic inches displacement, and 25 HP.

The piston rod is threaded into the crosshead, making the compression ratio adjustable. As it now stands, the piston clears the head by about 3/16' giving the high compression necessary for a diesel. Old timers have told me that a gas conversion head was available, lowering the compression and allowing the engine to run on natural gas. The use of low cost, or free fuel was likely a good selling point, considering the hard times of the 1930s.

The engine is equipped with roller main bearings, two on a side. These bearings are 2' wide, 7' o.d. and 5' i.d., making a very sturdy setup.

This engine will run on crude oil, and did most of its working life. It never saw fuel oil until I started running it for show.

For such a heavily built engine, it is not difficult to start. It had to start easily in remote places without battery or air starting aids.

To start the beast, install a fresh spark plug, pour about a tablespoon of gasoline into the head and about a half cup in the air intake. Close the air shutter to about inch, turn on the mag, and roll the flywheels backward into compression. The mag is timed 'late,' as the compression is so high, it is not possible to kick the piston very far forward. The gas will fire, and succeeding turns of the wheels will suck more gas into the cylinder, gaining speed. Let the fuel pump down onto the cam, and if all goes right, the engine will start running on fuel oil. The mag can then be turned off, and the engine will run almost unattended, only needing a few drops of oil on the governor linkage, and keep the lubricator filled.

The engine has an enclosed crank-case and will run in a hard rain without missing a lick. It's quite a nice engine.

I installed leman 'windows' in place of the inspection plates, so it's possible to see inside the crankcase, and inside the two gear boxes, making the engine more interesting for spectators.