Headless Jacobson

After a factory fire, this engine may have been made from spare parts

| July 2006


This headless hopper-cooled Jacobson came from the Arcade area of western New York, and then traveled to southeastern Arizona.

It is 48 inches long, 22 inches high and about 36 inches wide, with a 12-inch diameter friction brake clutch pulley. It has a 5-1/2-inch bore with a 4-inch stroke. The flywheels are 84 inches in circumference and 2-1/2 inches wide.

The castings on the engine are rather rough, giving the appearance of having been out in the weather. However, in critical areas, the castings are still machined smooth. Only the base has a clear casting number: K753. The bore diameter suggests a 5 HP engine. The Jacobson Gas and Gasoline Engines manual lists the 5 HP engines at 350 RPM, not the tagged 400 RPM. The tag, showing the engine's manufacture in Titusville, is of some interest as only a few Titusville engines are known, with the majority coming from the Warren, Pa., plant.

Another unique feature is the Wico magneto - most Jacobson engines feature the Webster magneto. The Jan. 12, 1924, Renewal Parts for Standard Jacobson Engines 2-1/2 HP to 16 HP Engine, lists the Wico magneto as a $22.50 option.

Some Jacobson experts I have talked with speculate that this engine may have been the 15th engine to have come from the Titusville plant. I have learned that the plant was opened in 1923 after a fire in the Warren plant the same year. If this is true, this engine may well have been assembled from parts on hand, providing an explanation for some of the different features. The extra 50 RPMs may have also been added to boost a 5 HP engine to a 6 HP engine, with the increased price.

Many Jacobson engine enthusiasts have looked at this engine with a shake of the head. Even so, it is an easy starter and will run all day long, or until it runs out of gas. It has a hearty thump that thrills even a skeptical Jacobson fan.