Groundbreaking engine technology appears fairly frequently, but few designs ever make it beyond the test bench and into production vehicles.

EcoMotors International's opposed-piston engine on the other hand might well have a future, as the company has just announced a $200 million deal to build its engines in China.

The Detroit-based engineering company revealed its opposed-piston, opposed-cylinder (OPOC) engine back in 2009, and little has been heard from the company since.

Automotive News (subscription required) reports EcoMotors has gone into partnership with China's Zhongding Power, which will build a plant in China's Anhui province with the capacity to build up to 150,000 OPOC engines per year.

EcoMotors and Zhongding have been working together on the engine since 2010, with production scheduled to begin in 2014.

We won't be seeing it under the hood of a regular production car any time soon though--instead, the design is likely to be used in a generator format, or in off-road and commercial vehicles.

The OPOC design looks complex, but as a two-stroke engine it's actually relatively simple.

The technology actually dates back to the early 1900s. Each cylinder, horizontally opposed as in a boxer engine, contains two pistons facing each other.

As a two-stroke design it's both lightweight and compact, with no need for cylinder heads or valvegear. It's also powerful for its capacity, with one power stroke per crank revolution, per cylinder.

Critics of the engine say the design isn't clean enough for regular road cars, due to the typical oil-burning requirements of two-stroke engines--but EcoMotors promises the engine meets government emissions regulations.

Some of the Chinese factory's capacity will be set aside for EcoMotors' own customers, but it isn't clear whether the engine will go into service in the U.S.

For EcoMotors, that may not matter anyway--a rapidly growing Chinese market provides the company with plenty of room for growth.