An Opposed Piston Engine with No Crankshaft

The perfection of the internal combustion engine has been sought for almost 150 years. In the process, some innovative and downright odd designs have emerged. Granada, Spain-based INNengine has developed an innovative opposed piston design that does away with crankshafts, replacing them with rotary cam tracks, the pistons functioning in a way similar to roller lifters in pushrod overhead valve engines. Mechanical simplicity and light weight are major advantages, as is a unique advantage offered by the cam system: variable compression ratio. The company has prototypes running now, and is developing engines for both automotive and aviation use. * * *Want to watch this podcast as a video? This Week in Engineering is available on engineering.com TV along with all of our other shows such as End of the Line, Designing the Future, Manufacturing the Future, and the Engineering Roundtable.