Hercules was a manufacturer of diesel engines until 1999. Due to economic downturns and losing government contracts, it no longer manufactures engines. The company, however, is far from defunct. As of 2010, it supplies all the parts for its original engines, and is heavily involved with engine re-manufacturing for various brands. The company still sells engines, and makes available to the general public the specifications for its current line of re-manufactured engines.
G1600 CAT 1404
The G1600 is a four-cylinder engine displacing 163 cubic inches. Its horsepower rating is a minimum of 20 to a maximum of 65 horsepower. Hercules states this engine is used on pallet trucks (also called hi-los), generators, some Jeeps, and wood chippers.
D2300 DT 3.7
The D2300 displaces 226 cubic inches. Its horsepower rating is from 27 to 84 horsepower through its rpm range. Some uses for this engine include shredders, small buses, and aircraft support vehicles, such as baggage carriers. Hercules states that some customers that use this engine include Chance Coach, Ingersol Rand, and the Ford Motor Co.
The D198ER is designed for military applications. It has a displacement of 198 cubic inches, and produces 58 horsepower at 2,600 rpm. It is 32 inches long, 24 inches wide, and 31 inches tall. It weighs 695 lbs. If you are designing a piece of equipment that uses this engine, Hercules recommends contacting the company in the early design stages for engineering assistance.