Parsell & Weed Engine

By Staff
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3678 North Ridge Road, Lockport, New York 14094

The pictured engine is a full size HP Parsell and Weed
reproduction. Plans for the engine were obtained from the 1900 book
Gas Engine Construction written by Henry Parsell and Arthur Weed.
This period publication illustrated detailed construction steps
from the making of patterns to machining of parts. Originally
offered in 1900, this engine was sold two ways: either as a
complete running assembly, or as a rough casting set, requiring
machining. A mechanically inclined person could even buy the book,
fabricate castings, and machine an engine himself.

The builders of this engine were able to locate a set of
unfinished cast iron castings and a first edition of the book
showing construction step by step. Several patterns were made for
the brass castings, such as the connecting rod ends, rocker arm and
valve cages. Numerous corrections were made to the original prints,
as several ‘questionable dimensions’ were found. The engine
is in essence an exact duplication of the original built 93 years
ago. A couple of subtle improvements were incorporated by the
builders such as o-ring seals and an improved piston.

Several distinguished features stand out, the first of which is
a pair of center mounted flywheels. Secondly, the governing
mechanism, which was found on a few different engines from that
era, but never really became successful. An other unique trait is
the cylinder and water jacket construction. A thin brass cylinder
containing the water and a cast iron sleeve were sandwiched between
two cast iron end collars, one of which the head was mounted

Propane is the fuel of choice for this engine; natural gas works
equally as well. Ignition is accomplished by high tension coil and
spark plug. Governing is of the hit and miss type, functioning by
inertia movement of a weighted spring loaded arm, which follows a
notch cut into the push rod. As the speed increases, the movement
of this arm changes, catching a detent on the rock arm, holding it

Construction of this engine and an identical twin were made from
Fall 1991 to Fall 1992 by John Rex, Chelmsford, Massachusetts and
Wayne Grenning, Lockport, New York.

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Preserving the History of Internal Combustion Engines