Not opposed to an opposed-piston engine
Opposed-piston engines are those characterized by pistons at both ends of each cylinder. This particular example comes from Monolith Engines Inc. in Wisconsin. The advantage of this idea is that four pistons can occupy the space normally needed for just one piston and piston rod and crank shaft. A 2-L engine putting out about 300 hp can weigh in at under 35 kg (about 77 lb.). Monolith Engine CEO Tom Dougherty, pictured here, says the design works best in situations where the engine runs at a constant speed, is for gas-powered generators. He also says the military is interested in the design because it can replace a conventional 3,000-lb. motor-generator with something weighing just 800 lb. The engine block casting seen here with Dougherty weighs about 38 lb.
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