1916 Denmo Truck: Putting The Denmo On Record

02 Denmo ad copy

Wow! Electric Lights and Starter!

You want an obscure ‘teen truck? You gots it: The Denmo.

The 1916 Denmo was “assembled” by the Denneen Motor Company of Cleveland, Ohio. From what I can tell, the company produced this truck in the late teens before being bought by General Motors. Company founder Francis S. Denneen went on to work with Boss Kettering at GM, the man credited with introducing both the electric starter (Cadillac) and the first modern ignition system (Delco).

By 1919 Francis Denneen was on to other endeavors, including establishing The Ohio Crankshaft Co. (TOCCO) in his garage in Cleveland. More on that later.


03 Denmo Truck

Pneumatic Fronts, Solid Rears

Those of you who are more conversant with pre-1920s trucks than I can comment on the truck’s features:

-Electric starting and lighting


-Boyce Moto-Meter

-Splitdorf generator

-Gould battery

-35 hp Wisconsin four-cylinder engine

-Grant-Lees three-speed transmission

-Borg & Beck clutch

-Torbensen axles

-and more

I’m pretty sure that at the time, electric starting and lighting weren’t found on all trucks–or cars, for that matter.


04 Engine Tranny

Wisconsin Engine & Grant-Lees Tranny

The 35 HP Wisconsin four-cylinder engine was governed to 20 mph. Talk about soporific, but with solid rear tires, a full load, and brakes only on the rear end, you probably wouldn’t want to go any faster.


01 Francis S. Denneen

Francis Stanislaus Denneen


This is big Frank. The Denmo truck was just a prelude for more important things to come.

Francis Stanislaus Denneen graduated with a masters in electrical engineering from Purdue University in 1903. After graduation, he spent three years with the Chalmers Motor Car Company and in other jobs before starting Denmo. His big contribution to automotive history, which all of us, and I mean ALL OF US (worldwide) use but are not necessarily aware of, was inventing the process for electrical induction hardening of metallic surfaces (i.e., crankshaft journals). Previously, hardening crankshaft journals involved a laborious and time-consuming process; Denneen’s process did the job in mere minutes. It was first used for the 1937 Packard V12, and is used to this day on virtually every car and truck engine made. Denneen and his process are in the Smithsonian in Washington, D.C.

Francis Denneen is my first cousin, three times removed (meaning he was born three generations before me). Learning about this guy is but one of the many joys of genealogical research.

Francis Denneen was born in 1879, in Ft. Covington, NY; he died in 1953, in Cleveland, OH. He and his wife left no children.