from the December 1997 issue of the
Hercules Engine News
by Glenn Karch
Did you ever see a 3 HP Arco brand engine built by Hercules? Several years Ago I found an instruction book and repair list put out by the Hardie Manufacturing Company of Hudson, Michigan, for their Arco brand gas engines. Much of the content was similar to that found in the Hercules manuals. However, this book dated in October 1925 covered only the three smaller size engines, including the 2, 21/2 and 31/2 HP sizes. In the very beginning of the Arco brand production, these same engines were rated it 11/2, 2 and 3 HP. I've been to A lot of shows and hive seen a lot of Arco engines, but they were all the two smaller sizes.
This past August, at the Tri-State Tractor and Gas Engine Show At Portland, Indiana, one of the vendors had in original 3 HP Arco for sale. It was the first that size that Id ever seen. It is pictured here, below. It is the typical Arco blue color with a hint of gray. In a day or two it sold to one of the exhibitors there and he had it running. The tag read HP 3E, serial number 223941, which dates it as a 1920. The first Arco brand engines were built in 1920. In my records there is another 1920. It is A 1 1/2, E, serial number 2 15051 . Arco production really got under way in late 1921 around 260000 serial number.
It is interesting in that the Arco brand engines were rerated to higher horsepower much earlier than the more common Hercules and Economy brands. Arco brand engines often carried the letters GH after the HP. The reason for this designation is unknown. About half of the Arcos observed have the Lunkenheimer fuel mixer on them while the rest have the more common ''J" type mixer. A few of the early ones had the regular Hercules ''log saw" mixer.
Production of Arco brand engines by Hercules continued until late in 1928, with serial number 371669 being the highest that I've observed. The Hardie Manufacturing Company then picked up another supplier of engines (builder unknown) for their sprayers. An example of one of those engines is shown here, above. Note the odd shaped fuel tank. The conical shape assured that there would be a fuel supply to mixer regardless of the topography the sprayer was operated on.
Coming next time will be more on summer show observations about Hercules and related engines.