The Achates Power opposed-piston engine is packed full of unique technology.The supercharged,turbocharged, diesel 3 cylinder makes use of six pistons, two of which operate in each cylinder./ via: Engineering Explained
source/image: Engineering Explained
It’s a two-stroke design, meaning every time the pistons come together a power stroke occurs, forcing both pistons away from one another and rotating their respective crankshafts.
The two crankshafts are geared together to a common output shaft, which powers the vehicle. Research has shown two-stroke opposed piston engines to be wildly efficient.
3 cylinder designs are the most efficient, and it’s possible to achieve brake thermal efficiencies as high as 55%, a massive improvement for road car engines. The engine in this video is a 2.7L 3-cylinder producing 270 HP and 480 lb-ft of torque.