Hercules Engine News

By Staff
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20601 Old State Road Haubstadt, Indiana 47639

Hercules built engines occasionally were purchased by concerns
that used them in the operation of their own business, or resold
them to specialized customers. Such was the case with the H. M.
Spence Company of Parkersburg, West Virginia. They purchased
Hercules built engines equipped to run on natural gas, or provided
their own conversion kit for that purpose. Spence at one time
apparently manufactured their own engines.

In early November a call was received from Ohio in regard to a 3
HP Hercules engine with a natural gas fuel mixer. The engine had an
H. M. Spence tag attached to it. I assumed that the engine was a
hit and miss with the Hercules made LP/NG mixer on it. Later in the
month, a call came from Petroleum, West Virginia, in regard to a 3
HP model SK Hercules built engine. After some discussion, it
suddenly became apparent that this was a throttling governed
natural gas engine, which I had never heard about before. It, too,
had the H. M. Spence tag. ‘

Early in December my oldest son and I made a trip to Virginia
and on the way back we detoured to Petroleum, West Virginia, to see
the throttling governed natural gas engine. Sure enough, there it
was. Simply put, it was an SK model with the kerosene mixer body
and pump removed and a special natural gas mixer substituted in its
place. The H. M. Spence Company must have provided a conversion
kit. It consisted of an adaptor that attached along with the
throttle body to the engine head. Too, the adaptor was fitted to
the natural gas mixer. A cross section of the H. M. Spence mixer is
illustrated here. It is interesting to note that Hercules also
supplied a similar but smaller version of this mixer for hit and
miss engines. It is attached to the regular J type gasoline mixer
that had a modified opening for the LP/NG mixer.

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