How to Identify a Hercules Engineby Ryan Hotchkiss
The Hercules Engine Company began production in the early 20th century, designing diesel engines for the U.S. trucking industry. Over the next 85 years, the company expanded their market to include production for the military. The military used Hercules engines for a variety of vehicles, including large transport vehicles airplanes and boats. As a result of the many roles Hercules engines have played, it is often difficult to identify a particular Hercules engine model. However, there are three ways to identify a Hercules engine.
Find the model number or letters stamped on the engine block. If you can find either of these model indicators, you know what Hercules engine you have. Unfortunately, the model numbers and letters rarely last as long as the engines; they are often covered with paint or corroded.
Look for the serial number. If you can find the serial number, you can find out what year the engine was manufactured and what model it is by searching a Hercules Engine Model catalog.
Take inventory of the specifications. If there are no identifying numbers or letters left on the engine, you are going to have to identify the Hercules using the engine's specs. Determine whether the engine runs on gas or diesel. Count the cylinders. Count the cylinder heads. Find out what kind of injection pump it has. Measure the length and height of the engine.