Two-stroke? Forced induction? Compression-ignition-capable? That is many unexpected engine technologies combined into a single engine.

The two-stroke engine is mostly a piece of history today, but there was a time when some of the coolest developments in engine technology were two-cycle engines.

Explore the history of two-stroke engines, from early adopters to their decline due to emissions regulations and advancing four-stroke tech.

A compression test is to determine how much pressure the engine makes, and a leakdown test measures its ability to hold pressure.

Two power strokes and two compression strokes per cycle. Generally, the biggest difference between a typical 4-stroke engine and the 6-stroke design is in the cam and valve timing.

In a two-cycle engine, the valving is designed to take advantage of both the up and down stroke of the motor to push exhaust and fresh air through the combustion chamber.

Read the tech article on Tuning Engine Compression, brought to you by the experts at Chevy High Performance Magazine ...

Discover how Alpha-Otto's RevForce engine transforms two-stroke engines with a rotary valve, enhancing efficiency and reducing emissions.

Some engines use a spark to ignite their fuel, and others rely on compression. What does all of that mean? And how do the two kinds of engines differ?

The end result was a two-stroke engine that produced up to 200 horsepower per liter, nearly double what was previously possible—the most powerful engine ever at the time.