20601 Old State Road, Haubstadt, Indiana 47639
The Hercules Thermoil story isn’t complete without
discussing ‘The Cummins Connection.’ Concurrent to the
design and development of the 1, 3, 6 and 8 HP Thermoil engines at
Hercules was the intense interest in diesel engines by a young
Columbus, Indiana man: Clessie Cummins.
He had turned his employer’s private garage into a small
machine shop. By some connection, he was doing some parts machining
work for the Hercules Gas Engine Company. He apparently was keenly
aware of the design work being done on the new Thermoils. He made a
trip to Chicago in October, 1918 to the R. M. Hvid Engineering
Company to see about obtaining rights to also produce the Hvid type
engine. The licensing fee being out of his reach, he returned to
Columbus. He convinced his employer and others that such an engine
would become popular, and with their backing formed the Cummins
Engine Company on February 3, 1919.
The first engine Cummins produced in April 1919 was the 6 HP
model C. They looked very similar to the 6 HP Thermoil Hercules was
building for Sears. Yours truly has seen #77C and knows of #142C.
Both are 6 HP Cummins, and they appear identical to the 6 HP
Thermoil in the previous story. The only exceptions being the water
hopper casting shape and the absence of pulley lugs on the
flywheels. By February, 1920, 22 had been sold. Apparently only 100
or so were produced. Only two are currently known to exist. #77 is
shown here in a rather poor picture yours truly took at the 1981
show at Portland, Indiana.
Hercules (1919) was now building the 6 and 8 model U Thermoil
for Sears, but lacked foundry capacity to expand into the and 3 HP
sizes. Hercules personnel suggested that Mr. Tippet from Sears
contact Cummins to build them. Sears awarded Cummins a contract to
build 4500 of the two small sizes. It is very likely that the
design for these engines was done at Hercules sometime earlier. The
1 HP size Cummins Thermoil is shown here (above right).
An early piece of Cummins literature states that Cummins engines
were built in l, 3, 6 and 8 HP sizes, but it is believed that the 6
HP was the only size actually built before the Sears opportunity
came along and the Cummins brand engines were phased out. Serial
number data available indicates that Cummins produced about 1500
(mostly in 1920) of the two small sizes before the bubble burst and
the market for them died. So far, at least 19 of these 1 and 3 HP
size are known to still exist. Cummins also produced that same year
some $10,000 worth of ‘injectors’ for Hercules to use on
the 6 and 8 HP Thermoils that they were building. That translates
into about 1000 injectors. Some injectors found on the Hercules
Thermoil 6 and 8 HP sizes have C E C (Cummins Engine Company)
stamped on the rim of the injector body.
A longer discussion of the Cummins Engine Company is beyond the
scope of ‘Hercules Engine News.’ If you desire some
information, check with your library for Clessie Cummins book, My
Days with the Diesel. The Indiana Magazine of History, December
1986, pages 303 to 333 contains an article by John Rowell who was
the historian for Cummins. It is titled, The Diesel Came, to
Indiana in the Horse and Buggy Days. There were also several
related articles in the Cummins employee magazines.
At least two advertising pieces and one instruction book on
these early Cummins engines exist. They were called ‘Cummins
Oil Engines.’ The small circle inset is of the fuel spraying
from the injector cup into the combustion chamber. The text and
illustrations are often strikingly similar to that put out in
literature for the Thermoil brand engines.