The Benz Engine

Learn about the intriguing history of the Benz gas engine and its inventor Karl Benz.

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Dr. Paul Harvey
The 12hp Benz at Coolspring Power Museum.

Way back in the early 1970s, while chatting with John Wilcox one day, I learned that the Buckeye Pipe Line Co. of Ohio experimented with many different brands of engines, unlike the Eureka of West Virginia, and National Transit of Pennsylvania; both of whom standardized one or two brands. Buckeye used De La Vergne, various types of Bessemer, St. Mary’s, Kleins, Ruston, and various farm engines. Surprisingly, they had imported three 12hp Benz Diesels for their Parent, Homan, and Clark stations. The Clark engine had experienced a catastrophic accident and was laying in their Blackrun tool yard. John had acquired the Homan engine, but the Parent engine was still available.

A black and white photo of an older man. A vintage black and white ad of a two men on a cart

Parent and Homan stations were in the Lodi, Ohio, area, and pumped crude oil to the bigger Lodi Station, which had the remains of a 65hp DH De La Vergne. Although the building was gone, many interesting items were laying about.

After some phone calls, my uncle Bruce and I were on our way in the faithful International pick-up to retrieve the engine. It turned out to be a difficult project with its one large flywheel and rounded marine style base. Finally, it was happily on its side and secured in the truck bed. Uncle Bruce and I safely arrived home after a good dinner along the way.

An older man in front of a gas engine.

Upon getting it home, I built what I intended to be a temporary base for it so I could lift it out of the truck vertically with the John Deere 2020 tractor and mount it for display and restoration. It lived this way in various locations for about 50 years until the fall of 2020 when Gordon Jones adopted it for restoration to be displayed in our proposed MAN building along with the MAN and Graz. It would represent 15 years of German diesel evolution.

Red engine with belts mounted on a wagon with large wheels.

Karl Benz was born November 25, 1844, in Muhlburg, Germany. His father passed away when he was 2 years old, but his mother, although poor, was able to provide a good education for him. He was a brilliant student and graduated from the University of Karlsruhe with a degree in engineering at age 19. He then moved to Mannheim and found work as a draftsman. Not satisfied, he then teamed up with August Ritter and opened the Iron Foundry and Mechanical Workshop. Here, he developed a 2-stroke cycle engine that was successful. Receiving a patent in June 1880, he continued to design both 2-stroke and 4-stroke cycle engines.

An aerial view of Mannheim, Germany.

In 1883, he founded the new Benz & Companie Rheische Gasmotern-Fabrik, commonly known as Benz & Cie. Here, he started to produce stationary engines. In 1885, Karl introduced the Benz Patent Motor Wagon, using a unique 4-stroke cycle engine.

A vintage ad for a gas engine

Coolspring Power Museum’s Benz Diesel was built in the Mannheim shops around 1915. In 1926, Benz & Cie. became Daimler-Benz after a merger. The first Mercedes Benz automobile was built that year.
So what is the significance of the Benz engine at CPM? One must recall that Dr. Rudolph Diesel placed his first air blast injection engine on the market in 1897. Yes, that was over 20 years later than Otto’s first successful gas engine. But the diesel introduced a new means of ignition and efficiency. It was here to stay. Our Benz engine represents 15-plus years of evolution and will be installed in the new building to accompany our 1903 MAN diesel and the 1904 Graz.

It is a typical German diesel engine, being vertical and with a single, large flywheel.

A side view of a gas engine

The CPM Benz definitely shows signs of a rather rough life in the oil field. Several modifications were made that included a water-cooled valve to pump compression pressure back into the starting air tank. It was also provided with a huge hand crank for manual starting. Besides the nice German oiler on the governor, a hand pump Lunkenheimer Alpha oiler was added for pre-lube. Good idea! Gordon Jones adopted it and took it to his home shop to restore over the winter.

A closeup of a multicolored gas engine

Our engine has two brass tags; one from the German Benz & Cie., the other from the sole distributor in New York City.

A closeup of a brass gas engine tag

A closeup of a brass gas engine tag

Gordon has been very dedicated to the restoration and it is progressing well. So much has to be repaired or reproduced, and I have been able to do smaller parts in my home shop. I have made many gaskets and Olson Gasket reproduced a fantastic copper gasket to seal the injector into the head. He had to repair almost every part.

An arrangement of tools on a table.

A closeup of tools on a table.

A gas engine in a workshop

Our good friend Dr. Friedrich Busch of Hof, Germany, probably the world’s expert on air blast injection diesels, provided me with copies of the appropriate Benz literature. Note that it is a Type R and built from 1915 to 1923. I would guess that ours is dated 1918 as that is about when Parent Station was erected. The chart depicts that they were built from one cylinder to six cylinders. That would place CPM’s Benz 21 years after Dr. Diesel’s first successful engine of 1897.

A vintage ad for a gas engine

Our great friend Adam Smith has reproduced and designed many parts for us. The fittings are carefully done to decipher the thread types. Being German, it has some metric, some Imperial, and other strange thread types — probably Benz. The frustration this must have caused for the Buckeye mechanics is evident by all the chisel marks on nuts that they did not have a wrench for. Adam’s work is fantastic!
We have this neat German engine, so what are we doing with it? Well, it will be the third engine in our upcoming ABI (Air Blast Injection) building. It will also house our 1903 Augsburg (MAN) and the 1904 Graz, which is still in Germany due to the Covid-19 pandemic. Hopefully, it will arrive this summer. This is an exciting project that is becoming a reality.

A chart for the different cylinders of the gas engine A set of tools

I certainly hope you have enjoyed this brief view of CPM’s Benz engine. Stay tuned for upcoming information about the fantastic new ABI building and what it will house.

A black and white drawing of a building

Email Dr. Paul Harvey at For more information on the Coolspring Power Museum, visit the Coolspring Power Museum’s website.

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