Hercules Engine News

Sorting out Drip Oilers

| January/February 2002

  • Essex oiler

  • Cylinder oilers

  • Essex oiler
  • Cylinder oilers

Shown above are pictures and catalog illustrations of #1-1/2 and #2 size cylinder oilers. Although the oilers in the photograph appear to both be from American Injector, the smaller oiler does not have their name on it.

Every open-crank gas engine requires a cylinder oiler of some kind. Did you ever wonder what is the correct cylinder drip oiler for your Hercules-built engine? A study of catalogs and parts diagrams would indicate that the proper oiler would have a cone-shaped top with the sloping part at about 27 or 28 degrees from the horizontal. Several manufacturers made oilers with that appearance. However, American Injector made oilers that appear to match the illustrations closely. Shown are catalog and parts illustrations and photographs of the #1-1/2 and #2 sizes. Although it is obvious that they are from the same manufacturer, the smaller one doesn't have the American Injector name on it.

This type of drip oiler was used starting with the Model B Sparta Economy in 1910 and continued through the S Hercules-built engines in 1929. These oilers have male threads on the bottom and require a 1/4-inch or 1/4-inch by 3/8-inch pipe connector to the oiler pipe. They have a check in the bottom of the lower part and a vent tube in the oil reservoir area. These help keep the cylinder blow-by from bubbling up through the oiler. They also feature a screw-in plug for the oil fill hole. The Model T Thermoil also uses this same type oiler. Although built by Hercules, the Model U Thermo oils have a built-in oiling system rather than the drip oiler. The later Model UA Thermo oils used a different drip oiler. Perhaps details on that will come later.

When you go shopping for the correct style of oiler, you will quickly find out that many oilers offered for sale at shows and swap meets are the machine-oiler type. The supply of good, original gas engine oilers is getting quite picked over by now. New gas engine oilers, somewhat similar to those used on Hercules related engines, are still being made and they can be obtained from several of the suppliers who advertise in GEM. The machine oilers contain no check or vent tube. Often times they are troublesome when used as a gas engine cylinder oiler. Quite often they also have a swing-aside cap for the oil fill hole rather than a screw-in plug. This usually allows rain water in and causes cloudy oil.

Shown above is a photograph and a parts illustration of an Essex oiler. The oiler in the photograph came from a 1-3/4 HP Model XK Economy.

With the introduction of the X model engines in 1928, a different cylinder oiler was used on the three smaller size engines. They were made by the Essex Brass Company. The top and bottom of the oil reservoir area is flat and it has 1/4-inch female pipe threads so it can be screwed directly onto the oiler pipe with no connector. They have no check in the bottom, but there is the typical vent tube in the oil reservoir. They have a swing-aside cover for the oil hole, which causes the cloudy oil problem if rained on. The 6 HP and 8 HP used an Essex oiler, too, but it had the male threaded base. An example is shown from the parts diagrams, along with a photograph of the oiler off of a 1-3/4 HP Model XK Economy.


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